Patents by Inventor Yuji Araoka
Yuji Araoka 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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Publication number: 20220186331Abstract: This electric resistance-welded steel tube for a hollow stabilizer is an electric resistance-welded steel tube for a hollow stabilizer including a base material portion and a weld, in which the base material portion has predetermined chemical components, a wall thickness of the base material portion is 2.0 to 6.Type: ApplicationFiled: March 27, 2020Publication date: June 16, 2022Inventors: Yukinobu NAGATA, Yuki MOTEGI, Yuji ARAOKA, Ken OU
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Patent number: 10350681Abstract: A high strength titanium alloy member with superior fatigue resistance, and a production method therefor, are provided. The production method includes preparing a raw material made of titanium alloy, nitriding the raw material to form a nitrogen-containing raw material by generating a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the raw material, mixing the raw material and the nitrogen-containing raw material to yield a nitrogen-containing mixed material, sintering the nitrogen-containing mixed material to obtain a sintered titanium alloy member by bonding the material together and uniformly diffusing nitrogen in solid solution from the nitrogen-containing raw material to the entire interior portion of the sintered titanium alloy member, hot plastic forming and/or heat treating the sintered titanium alloy member to obtain a processed member, and surface treating the processed member to provide compressive residual stress.Type: GrantFiled: April 27, 2012Date of Patent: July 16, 2019Assignee: NHK SPRING CO., LTD.Inventors: Tohru Shiraishi, Yoshiki Ono, Yuji Araoka
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Patent number: 10151019Abstract: A production method for a titanium alloy member includes preparing a titanium alloy material for sintering as a raw material of a sintered body; nitriding the titanium alloy material for sintering, thereby forming a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the titanium alloy material for sintering and yielding a nitrogen-containing titanium alloy material for sintering; mixing the titanium alloy material for sintering and the nitrogen-containing titanium alloy material for sintering, thereby yielding a titanium alloy material for sintering mixed with nitrogen-containing titanium alloy material; sintering the titanium alloy material for sintering mixed with nitrogen-containing titanium alloy material, thereby bonding the material each other and dispersing nitrogen contained in the nitrogen-containing titanium alloy material for sintering in a condition in which nitrogen is uniformly dispersed into an entire inner portion of the sintered body by solid solution.Type: GrantFiled: August 15, 2011Date of Patent: December 11, 2018Assignee: NHK SPRING CO., LTD.Inventors: Yuji Araoka, Tohru Shiraishi, Yoshiki Ono
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Patent number: 9920399Abstract: A titanium alloy member with high strength and high proof stress not only in the surface but also inside, using a general and inexpensive ?-? type titanium alloy, and a production method therefor, are provided. The production method includes preparing a raw material made of titanium alloy, nitriding the raw material to form a nitrogen-containing raw material by generating a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the raw material, mixing the raw material and the nitrogen-containing raw material to yield a nitrogen-containing mixed material, sintering the nitrogen-containing mixed material to obtain a sintered titanium alloy member by bonding the material together and uniformly diffusing nitrogen in solid solution from the nitrogen-containing raw material to the entire interior portion of the sintered titanium alloy member, and hot plastic forming the sintered titanium alloy member.Type: GrantFiled: April 27, 2012Date of Patent: March 20, 2018Assignee: NHK SPRING CO., LTD.Inventors: Tohru Shiraishi, Yoshiki Ono, Yuji Araoka
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Patent number: 9920403Abstract: A high-strength magnesium alloy member is suitable for products in which at least one of bending stress and twisting stress primarily acts. The member has required elongation and 0.2% proof stress, whereby strength and formability are superior, and has higher strength and large compressive residual stress in the vicinity of the surface of a wire rod. In the magnesium alloy member formed as a wire rod in which at least one of bending stress and twisting stress primarily acts, the wire rod includes a surface portion having the highest hardness of 170 HV or more in the vicinity of the surface and an inner portion having a 0.2% proof stress of 550 MPa or more and an elongation of 5% or more, and the wire rod has the highest compressive residue stress in the vicinity of the surface of 50 MPa or more.Type: GrantFiled: March 29, 2013Date of Patent: March 20, 2018Assignee: NHK SPRING CO., LTD.Inventors: Yuji Araoka, Tohru Shiraishi, Yoshiki Ono
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Patent number: 9570948Abstract: A magnet plate used for a rotor core of a motor, includes a magnetic pole portion being set between an outer peripheral edge of a body portion and a magnet slot and having a radial width being smaller than a radial sectional width of the permanent magnet, and a higher hardness portion being formed into a hook shape along an end corner of the magnet slot and have a smaller width than the radial sectional width of the permanent magnet.Type: GrantFiled: April 15, 2014Date of Patent: February 14, 2017Assignee: NHK Spring Co., Ltd.Inventors: Yohei Kameda, Kazuo Iwata, Yuji Araoka, Yoshiki Ono
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Publication number: 20160065015Abstract: A magnet plate used for a rotor core of a motor, includes a magnetic pole portion being set between an outer peripheral edge of a body portion and a magnet slot and having a radial width being smaller than a radial sectional width of the permanent magnet, and a higher hardness portion being formed into a hook shape along an end corner of the magnet slot and have a smaller width than the radial sectional width of the permanent magnet.Type: ApplicationFiled: April 15, 2014Publication date: March 3, 2016Applicant: NHK Spring Co., Ltd.Inventors: Yohei KAMEDA, Kazuo IWATA, Yuji ARAOKA, Yoshiki ONO
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Publication number: 20150104669Abstract: A high-strength magnesium alloy member is suitable for products in which at least one of bending stress and twisting stress primarily acts. The member has required elongation and 0.2% proof stress, whereby strength and formability are superior, and has higher strength and large compressive residual stress in the vicinity of the surface of a wire rod. In the magnesium alloy member formed as a wire rod in which at least one of bending stress and twisting stress primarily acts, the wire rod includes a surface portion having the highest hardness of 170 HV or more in the vicinity of the surface and an inner portion having a 0.2% proof stress of 550 MPa or more and an elongation of 5% or more, and the wire rod has the highest compressive residue stress in the vicinity of the surface of 50 MPa or more.Type: ApplicationFiled: March 29, 2013Publication date: April 16, 2015Applicant: NHK SPRIG CO., LTD.Inventors: Yuji Araoka, Tohru Shiraishi, Yoshiki Ono
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Publication number: 20140212319Abstract: A high strength titanium alloy member with superior fatigue resistance, and a production method therefor, are provided. The production method includes preparing a raw material made of titanium alloy, nitriding the raw material to form a nitrogen-containing raw material by generating a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the raw material, mixing the raw material and the nitrogen-containing raw material to yield a nitrogen-containing mixed material, sintering the nitrogen-containing mixed material to obtain a sintered titanium alloy member by bonding the material together and uniformly diffusing nitrogen in solid solution from the nitrogen-containing raw material to the entire interior portion of the sintered titanium alloy member, hot plastic forming and/or heat treating the sintered titanium alloy member to obtain a processed member, and surface treating the processed member to provide compressive residual stress.Type: ApplicationFiled: April 27, 2012Publication date: July 31, 2014Applicant: NHK SPRING CO., LTD.Inventors: Tohru Shiraishi, Yoshiki Ono, Yuji Araoka
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Publication number: 20140112819Abstract: A titanium alloy member with high strength and high proof stress not only in the surface but also inside, using a general and inexpensive ?-? type titanium alloy, and a production method therefor, are provided. The production method includes preparing a raw material made of titanium alloy, nitriding the raw material to form a nitrogen-containing raw material by generating a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the raw material, mixing the raw material and the nitrogen-containing raw material to yield a nitrogen-containing mixed material, sintering the nitrogen-containing mixed material to obtain a sintered titanium alloy member by bonding the material together and uniformly diffusing nitrogen in solid solution from the nitrogen-containing raw material to the entire interior portion of the sintered titanium alloy member, and hot plastic forming the sintered titanium alloy member.Type: ApplicationFiled: April 27, 2012Publication date: April 24, 2014Applicant: NHK SPRING CO., LTD.Inventors: Tohru Shiraishi, Yoshiki Ono, Yuji Araoka
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Publication number: 20130195711Abstract: A high-strength magnesium alloy wire rod suitable for products in which at least one of bending stress and twisting stress primarily acts is provided. The wire rod has required elongation and 0.2% proof stress, whereby strength and formability are superior, and has higher strength in the vicinity of the surface. In the wire rod, the surface portion has the highest hardness in a cross section of the wire rod, the highest hardness is 170 HV or more, and the inner portion has a 0.2% proof stress of 550 MPa or more and an elongation of 5% or more.Type: ApplicationFiled: October 14, 2011Publication date: August 1, 2013Applicant: NHK SPRING CO., LTD.Inventors: Yuji Araoka, Tohru Shiraishi, Yoshiki Ono
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Publication number: 20130149183Abstract: A production method for a titanium alloy member includes preparing a titanium alloy material for sintering as a raw material of a sintered body; nitriding the titanium alloy material for sintering, thereby forming a nitrogen compound layer and/or a nitrogen solid solution layer in a surface layer of the titanium alloy material for sintering and yielding a nitrogen-containing titanium alloy material for sintering; mixing the titanium alloy material for sintering and the nitrogen-containing titanium alloy material for sintering, thereby yielding a titanium alloy material for sintering mixed with nitrogen-containing titanium alloy material; sintering the titanium alloy material for sintering mixed with nitrogen-containing titanium alloy material, thereby bonding the material each other and dispersing nitrogen contained in the nitrogen-containing titanium alloy material for sintering in a condition in which nitrogen is uniformly dispersed into an entire inner portion of the sintered body by solid solution.Type: ApplicationFiled: August 15, 2011Publication date: June 13, 2013Applicant: NHK SPRING CO., LTD.Inventors: Yuji Araoka, Tohru Shiraishi, Yoshiki Ono