Patents by Inventor Mitsuharu Yamagata

Mitsuharu Yamagata 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: 11131612
    Abstract: There is provided a method for estimating a hardness of a cold worked component including: preparing a test piece for hardness measurement having a dent portion of a shape corresponding to a shape of the contact surface of the punch by using a mounting base on which a test piece is mounted and a punch of which a contact surface to be in contact with the test piece is a curved surface, and compressing the test piece mounted on the mounting base using the punch; measuring hardnesses of the test piece for hardness measurement at a plurality of hardness measurement positions in a measurement direction while taking, as the measurement direction, a direction in the dent portion in which a sheet thickness changes; performing numerical analysis to calculate equivalent plastic strains of the test piece for hardness measurement, and acquiring a hardness-equivalent plastic strain curve on the basis of the hardnesses and the equivalent plastic strains at the hardness measurement positions; and specifying a hardness from
    Type: Grant
    Filed: March 15, 2018
    Date of Patent: September 28, 2021
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Mitsuharu Yamagata, Nobuo Yoshikawa, Yasushi Tsukano
  • Patent number: 10857582
    Abstract: A method of manufacturing a tooth-shaped component including a process of draw-forming a workpiece so as to obtain a cylindrical container, which has a bottom surface portion and a side surface portion; a diameter-reducing process of reducing the diameter of a particular part in which a tooth tip portion is to be formed in the side surface portion of the cylindrical container, so as to increase the thickness of a corner portion such that an external shape of the corner portion between the bottom surface portion and the side surface portion satisfies the following conditional expression (?R+?H)?2t; and a tooth shape-forming process of forming the tooth tip portion in the particular part of the cylindrical container reduced in diameter in the diameter-reducing process, so as to obtain a tooth-shaped component which has the bottom surface portion, the side surface portion, and the tooth tip portion.
    Type: Grant
    Filed: January 7, 2016
    Date of Patent: December 8, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Mitsuharu Yamagata, Shuji Yamamoto, Yasushi Tsukano
  • Patent number: 10675673
    Abstract: A method of manufacturing a mechanical part of the present invention includes a first process of forming, by performing a folding processing to an end portion of the material, a portion to be processed having a structure, in which a plurality of layers respectively having a thickness corresponding to a plate thickness of a material overlap each other, in the material such that a plate thickness direction of the layer is orthogonal to a plate thickness direction of the material; and a second process of changing, by performing a forging processing to the portion to be processed, a shape of the portion to be processed to a target shape while press-welding the layers of the portion to be processed to each other by plastic deformation.
    Type: Grant
    Filed: January 7, 2016
    Date of Patent: June 9, 2020
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Mitsuharu Yamagata, Shuji Yamamoto, Yasuhiro Wada
  • Publication number: 20200116608
    Abstract: There is provided a method for estimating a hardness of a cold worked component including: preparing a test piece for hardness measurement having a dent portion of a shape corresponding to a shape of the contact surface of the punch by using a mounting base on which a test piece is mounted and a punch of which a contact surface to be in contact with the test piece is a curved surface, and compressing the test piece mounted on the mounting base using the punch; measuring hardnesses of the test piece for hardness measurement at a plurality of hardness measurement positions in a measurement direction while taking, as the measurement direction, a direction in the dent portion in which a sheet thickness changes; performing numerical analysis to calculate equivalent plastic strains of the test piece for hardness measurement, and acquiring a hardness-equivalent plastic strain curve on the basis of the hardnesses and the equivalent plastic strains at the hardness measurement positions; and specifying a hardness from
    Type: Application
    Filed: March 15, 2018
    Publication date: April 16, 2020
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Mitsuharu YAMAGATA, Nobuo YOSHIKAWA, Yasushi TSUKANO
  • Publication number: 20190321873
    Abstract: A press forming method includes a first process of obtaining a pressing force applied to each portion of a tool by an workpiece material during press forming while independently driving the respective each portion of the tool divided into multiple portions and press forming the workpiece material, and a second process of adjusting at least one of an applied driving force, an applied driving speed, and an applied driving timing for each portion of the tool to cause a processing portion of the workpiece material in which the state approaching an overload state is detected based on the pressing force to flow to other processing portions of the workpiece material.
    Type: Application
    Filed: June 28, 2019
    Publication date: October 24, 2019
    Applicant: NIPPON STEEL CORPORATION
    Inventors: Yasuhiro WADA, Shuji YAMAMOTO, Mitsuharu YAMAGATA
  • Patent number: 10376941
    Abstract: A press forming method includes a first process of obtaining a pressing force applied to each portion of a tool by an workpiece material during press forming while independently driving the respective each portion of the tool divided into multiple portions and press forming the workpiece material, and a second process of adjusting at least one of an applied driving force, an applied driving speed, and an applied driving timing for each portion of the tool to cause a processing portion of the workpiece material in which the state approaching an overload state is detected based on the pressing force to flow to other processing portions of the workpiece material.
    Type: Grant
    Filed: May 13, 2015
    Date of Patent: August 13, 2019
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Yasuhiro Wada, Shuji Yamamoto, Mitsuharu Yamagata
  • Patent number: 10029296
    Abstract: A forming die includes: a lower forming die having a bottom part and a side wall part; an upper forming die that is movable toward the bottom part of the lower forming die along an axis parallel to the side wall part of the lower forming die; and a push-in die that is movable toward the bottom part of the lower forming die along the axis between the side wall part of the lower forming die and the upper forming die.
    Type: Grant
    Filed: April 20, 2015
    Date of Patent: July 24, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu Yamagata, Shuji Yamamoto, Takeshi Kawachi
  • Publication number: 20180021836
    Abstract: There is provided a method of manufacturing a tooth-shaped component including drawing process of draw-forming a workpiece so as to obtain a cylindrical container which has a bottom surface portion and a side surface portion; diameter-reducing process of reducing a diameter of a particular part in which a tooth tip portion is to be formed in the side surface portion of the cylindrical container, so as to increase a thickness of a corner portion such that an external shape of the corner portion between the bottom surface portion and the side surface portion satisfies the following conditional expression (1); and tooth shape-forming process of forming the tooth tip portion in the particular part of the cylindrical container reduced in diameter in the diameter-reducing process, so as to obtain a tooth-shaped component which has the bottom surface portion, the side surface portion, and the tooth tip portion.
    Type: Application
    Filed: January 7, 2016
    Publication date: January 25, 2018
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu YAMAGATA, Shuji YAMAMOTO, Yasushi TSUKANO
  • Publication number: 20170348763
    Abstract: A method of manufacturing a mechanical part of the present invention includes a first process of forming, by performing a folding processing to an end portion of the material, a portion to be processed having a structure, in which a plurality of layers respectively having a thickness corresponding to a plate thickness of a material overlap each other, in the material such that a plate thickness direction of the layer is orthogonal to a plate thickness direction of the material; and a second process of changing, by performing a forging processing to the portion to be processed, a shape of the portion to be processed to a target shape while press-welding the layers of the portion to be processed to each other by plastic deformation.
    Type: Application
    Filed: January 7, 2016
    Publication date: December 7, 2017
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu YAMAGATA, Shuji YAMAMOTO, Yasuhiro WADA
  • Patent number: 9707617
    Abstract: While a compression part (B1) in a bottom wall part of a cup-shaped workpiece (B) is compressed by an inner punch (11) and an inner die (14) and moved in a direction to get away from an intermediate die (15), the inner die (14) is pushed toward the inner punch (11); and a compression part (B2) being an outer end portion in a radial direction of the workpiece (B) is compressed by an outer punch (13) and an outer die (16) and moved in an direction to approach the intermediate die (15), to thereby suppress the workpiece (B) in the compression part (B2) from material-flowing in a direction to get away from a central axis (10), whereby thickness reduction processing of the compression part (B1) and thickness increase processing of a vertical wall part (B3) of the workpiece (B) sandwiched by an intermediate punch (12) and the inner die (15) and a vertical wall part (B4) of the workpiece (B) sandwiched by the intermediate punch (12) and an outer die (16) are performed.
    Type: Grant
    Filed: November 7, 2013
    Date of Patent: July 18, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu Yamagata, Shuji Yamamoto, Yasuhiro Wada
  • Publication number: 20170106431
    Abstract: A forming die includes: a lower forming die having a bottom part and a side wall part; an upper forming die that is movable toward the bottom part of the lower forming die along an axis parallel to the side wall part of the lower forming die; and a push-in die that is movable toward the bottom part of the lower forming die along the axis between the side wall part of the lower forming die and the upper forming die.
    Type: Application
    Filed: April 20, 2015
    Publication date: April 20, 2017
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu YAMAGATA, Shuji YAMAMOTO, Takeshi KAWACHI
  • Publication number: 20170100761
    Abstract: A press forming method includes a first process of obtaining a pressing force applied to each portion of a tool by an workpiece material during press forming while independently driving the respective each portion of the tool divided into multiple portions and press forming the workpiece material, and a second process of adjusting at least one of an applied driving force, an applied driving speed, and an applied driving timing for each portion of the tool to cause a processing portion of the workpiece material in which the state approaching an overload state is detected based on the pressing force to flow to other processing portions of the workpiece material.
    Type: Application
    Filed: May 13, 2015
    Publication date: April 13, 2017
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Yasuhiro WADA, Shuji YAMAMOTO, Mitsuharu YAMAGATA
  • Patent number: 9505047
    Abstract: A press-forming method includes: a step of forming a first cup-shaped workpiece (B); a step of moving an axial pressing punch (13) relatively to a die (15) to abut on a cup opening end (B21) of a cup sidewall portion (B2), and while constraining the cup opening end (B21), moving a second-stage forming punch (11) relatively to the die (15) to insert the second-stage forming punch (11) into a second die hole portion (155), and pushing a part of the first cup-shaped workpiece into the second die hole portion (155) through a second die shoulder portion (154), to thereby reduce the cup sidewall portion (B2) in diameter and thicken the cup sidewall portion (B2); and a step of, in a state of the constraint of the cup opening end (B21) by the axial pressing punch (13) being released, moving the second-stage forming punch (11) relatively to the die (15) and further pushing the first cup-shaped workpiece deeper in the second die hole portion (155), to thereby form a second cup-shaped workpiece smaller in diameter than
    Type: Grant
    Filed: December 27, 2013
    Date of Patent: November 29, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu Yamagata, Shuji Yamamoto, Yasuhiro Wada
  • Patent number: 9468971
    Abstract: An inner punch (11), an outer punch (12), and a die (13) are disposed on the same center axis (10). The outer punch (12) is disposed so as to be apart from the inner punch (11) in a radial direction perpendicular to the center axis (10) by a first space S1 which is larger than a plate thickness T of a cup longitudinal wall portion (A2). Further, an inner peripheral surface of the outer punch (12) has, on its die (13) side, a punch shoulder R portion (12A) widening as it goes toward the die (13).
    Type: Grant
    Filed: December 26, 2013
    Date of Patent: October 18, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu Yamagata, Shuji Yamamoto, Yasuhiro Wada
  • Patent number: 9452461
    Abstract: A press forming apparatus (1a) consecutively carries out: a first step of pushing a flat plate-shaped workpiece into a die (14) by a forming punch (11), to form the workpiece into a cup-shaped workpiece (B); a second step of making the cup-shaped workpiece (B) move relatively to a position where a space (S2) is formed between a cup bottom part (B2) and the forming punch (11) by a holding down member (12) abutting on an end part of a cup vertical wall part (B1); and a third step of making a counter punch (13) approach the forming punch (11), to push a cup bottom part (B2) to a forming punch (11) side so that the cup bottom part (B2) is compressed by the forming punch (11) and the counter punch (13), making a material of the cup vertical wall part (B1) flow to a cup shoulder part (B3), thereby to thicken the cup shoulder part (B3).
    Type: Grant
    Filed: December 26, 2013
    Date of Patent: September 27, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu Yamagata, Shuji Yamamoto, Yasuhiro Wada
  • Patent number: 9421597
    Abstract: A press mold includes an inner punch (23), an intermediate punch (24) disposed along an outer periphery of the inner punch (23) and having an intermediate punch inclined portion (24a) at a leading end, an outer punch (25) disposed along an outer periphery of the intermediate punch (24), and a die (27) having a die inclined portion (27a) facing the intermediate punch inclined portion (24a), central axes (20) of all of which are coaxially disposed. While a bottom portion of a bottomed container (22) is constrained by the inner punch (23) and the die (27), an end portion of the bottomed container (22) is pressed by the outer punch (25), and the intermediate punch (24) is moved in a direction opposite a direction in which the outer punch (25) is pressed, whereby a bottomed container inclined portion (22a) of the bottomed container (22) sandwiched by the intermediate punch inclined portion (24a) and the die inclined portion (27a) is thickened.
    Type: Grant
    Filed: October 22, 2013
    Date of Patent: August 23, 2016
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shuji Yamamoto, Yasuhiro Wada, Mitsuharu Yamagata
  • Publication number: 20150367398
    Abstract: A press forming apparatus (1a) consecutively carries out: a first step of pushing a flat plate-shaped workpiece into a die (14) by a forming punch (11), to form the workpiece into a cup-shaped workpiece (B); a second step of making the cup-shaped workpiece (B) move relatively to a position where a space (S2) is formed between a cup bottom part (B2) and the forming punch (11) by a holding down member (12) abutting on an end part of a cup vertical wall part (B1); and a third step of making a counter punch (13) approach the forming punch (11), to push a cup bottom part (B2) to a forming punch (11) side so that the cup bottom part (B2) is compressed by the forming punch (11) and the counter punch (13), making a material of the cup vertical wall part (B1) flow to a cup shoulder part (B3), thereby to thicken the cup shoulder part (B3).
    Type: Application
    Filed: December 26, 2013
    Publication date: December 24, 2015
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu YAMAGATA, Shuji YAMAMOTO, Yasuhiro WADA
  • Publication number: 20150336152
    Abstract: A press-forming method includes: a step of forming a first cup-shaped workpiece (B); a step of moving an axial pressing punch (13) relatively to a die (15) to abut on a cup opening end (B21) of a cup sidewall portion (B2), and while constraining the cup opening end (B21), moving a second-stage forming punch (11) relatively to the die (15) to insert the second-stage forming punch (11) into a second die hole portion (155), and pushing a part of the first cup-shaped workpiece into the second die hole portion (155) through a second die shoulder portion (154), to thereby reduce the cup sidewall portion (B2) in diameter and thicken the cup sidewall portion (B2); and a step of, in a state of the constraint of the cup opening end (B21) by the axial pressing punch (13) being released, moving the second-stage forming punch (11) relatively to the die (15) and further pushing the first cup-shaped workpiece deeper in the second die hole portion (155), to thereby form a second cup-shaped workpiece smaller in diameter than
    Type: Application
    Filed: December 27, 2013
    Publication date: November 26, 2015
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu YAMAGATA, Shuji YAMAMOTO, Yasuhiro WADA
  • Publication number: 20150314357
    Abstract: An inner punch (11), an outer punch (12), and a die (13) are disposed on the same center axis (10). The outer punch (12) is disposed so as to be apart from the inner punch (11) in a radial direction perpendicular to the center axis (10) by a first space S1 which is larger than a plate thickness T of a cup longitudinal wall portion (A2). Further, an inner peripheral surface of the outer punch (12) has, on its die (13) side, a punch shoulder R portion (12A) widening as it goes toward the die (13).
    Type: Application
    Filed: December 26, 2013
    Publication date: November 5, 2015
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Mitsuharu YAMAGATA, Shuji YAMAMOTO, Yasuhiro WADA
  • Publication number: 20150239029
    Abstract: A press mold includes an inner punch (23), an intermediate punch (24) disposed along an outer periphery of the inner punch (23) and having an intermediate punch inclined portion (24a) at a leading end, an outer punch (25) disposed along an outer periphery of the intermediate punch (24), and a die (27) having a die inclined portion (27a) facing the intermediate punch inclined portion (24a), central axes (20) of all of which are coaxially disposed. While a bottom portion of a bottomed container (22) is constrained by the inner punch (23) and the die (27), an end portion of the bottomed container (22) is pressed by the outer punch (25), and the intermediate punch (24) is moved in a direction opposite a direction in which the outer punch (25) is pressed, whereby a bottomed container inclined portion (22a) of the bottomed container (22) sandwiched by the intermediate punch inclined portion (24a) and the die inclined portion (27a) is thickened.
    Type: Application
    Filed: October 22, 2013
    Publication date: August 27, 2015
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Shuji Yamamoto, Yasuhiro Wada, Mitsuharu Yamagata