Patents by Inventor Junichi Kurokawa

Junichi Kurokawa 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).

  • Publication number: 20190363517
    Abstract: A laser oscillator includes: a plurality of laser media to emit laser beams having different wavelengths; a diffraction grating to emit, in a superimposed state, the laser beams incident from the laser media; a partially reflective element to reflect part of the laser beams emitted from the diffraction grating and return the part of the laser beams to the diffraction grating, and to transmit a remainder; and a plurality of lenses each disposed between a corresponding one of the laser media and the diffraction grating. The lenses are each disposed in an optical path formed between a corresponding one of the laser media and the diffraction grating, and the lenses superimpose the laser beams from the laser media on an incident surface of the diffraction grating such that the laser beams have an equal outer diameter.
    Type: Application
    Filed: March 1, 2017
    Publication date: November 28, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Junichi NISHIMAE, Tomotaka KATSURA, Daiji MORITA, Hiroaki KUROKAWA
  • Patent number: 10464120
    Abstract: A method for producing a forged crankshaft includes a die forging step of forming a forged blank having a crankshaft shape by die forging, and a pressing step of pressing the forged blank by a first dies. The forged blank includes first excess portions attached to some or all of crank arms each incorporating a counterweight, each of the first excess portions protrudes from a side portion of the crank arm, in a region near a journal. In the pressing step, the first excess portions are deformed by the first dies such that each of the first excess portions bulges toward a pin. This facilitates the production of a forged crankshaft with a reduced weight and assured stiffness.
    Type: Grant
    Filed: December 10, 2015
    Date of Patent: November 5, 2019
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Kenji Tamura, Junichi Okubo, Ken Yoshino, Kunihiro Yabuno, Hiroyuki Kurokawa, Tomohisa Yamashita, Sho Takamoto, Koichiro Ishihara
  • Patent number: 10441995
    Abstract: The disclosed production method includes a die forging step of obtaining a forged blank with flash having a crankshaft shape, and a trimming step of removing the flash from the forged blank while nipping the forged blank with a pair of holding dies. In the forged blank, at least one of the rough crank arms have, in a region near an adjacent rough pin, a first excess portion protruding from an outer periphery of a side portion of the rough crank arm. When the forged blank is nipped with the pair of holding dies, the first excess portion is deformed by the pair of holding dies to bulge toward an adjacent rough journal.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: October 15, 2019
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Sho Takamoto, Kenji Tamura, Tomohisa Yamashita, Kunihiro Yabuno, Ken Yoshino, Hiroyuki Kurokawa, Junichi Okubo, Koichiro Ishihara
  • Patent number: 10413965
    Abstract: The disclosed production method includes a rough forging step of performing die forging to obtain a rough forged blank with flash having a crankshaft shape, and a finish forging step of applying die forging by use of a first pair of dies to the rough forged blank to obtain a finish forged blank with flash. In the rough forged blank, at least one of the rough crank arms have, in a region near an adjacent rough pin, a first excess portion protruding from an outer periphery of a side portion of the rough crank arm. During the die forging in the finish forging step, the first excess portion is deformed by the first pair of dies to bulge toward an adjacent rough journal.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: September 17, 2019
    Assignee: NIPPON STEEL CORPORATION
    Inventors: Sho Takamoto, Kenji Tamura, Tomohisa Yamashita, Kunihiro Yabuno, Ken Yoshino, Hiroyuki Kurokawa, Junichi Okubo, Koichiro Ishihara
  • Publication number: 20190252844
    Abstract: A laser oscillator includes: an external resonator configured to include laser media to emit laser beams having different wavelengths; and a partially reflective mirror to transmit part of the laser beams and reflect and return a remainder toward the laser media. The external resonator includes therein: a diffraction grating to perform wavelength coupling on the laser beams having different wavelengths emitted from the laser media so as to superimpose the laser beams into one laser beam and to emit, to the partially reflective mirror, the one laser beam; and a prism that is placed between the laser media and the diffraction grating and that superimposes the laser beams into one laser beam on the diffraction grating, the prism including two surfaces forming an apex angle, one of the two surfaces being an incident surface and another of the two surfaces being an exit surface.
    Type: Application
    Filed: February 13, 2017
    Publication date: August 15, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Junichi NISHIMAE, Tomotaka KATSURA, Daiji MORITA, Hiroaki KUROKAWA
  • Patent number: 10350671
    Abstract: A method for producing a forged crankshaft includes: a preforming step of forming a preformed blank with no flash, the preformed blank including a shape of the crankshaft, wherein the crank arm have excess projecting portions at an outer peripheries of side portions of the crank arm near the crank pin; a die forging step of forming a forged blank with flash by pressing the preformed blank with a pair of first dies; and a trimming step of removing the flash from the forged blank. In the die forging step, while a second die is abutted against a journal-side surface of the crank arm and holds the surface, the excess projecting portions of the crank arm are deformed by the first dies so as to increase the side portions of the crank arm in thickness.
    Type: Grant
    Filed: July 9, 2015
    Date of Patent: July 16, 2019
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Kenji Tamura, Junichi Okubo, Koichiro Ishihara, Ken Yoshino, Kunihiro Yabuno, Hiroyuki Kurokawa, Tomohisa Yamashita, Sho Takamoto
  • Patent number: 8469654
    Abstract: A rotary-type fluid machine which enables practical and effective operation in an extremely low specific speed range. The rotary-type fluid machine (1, 1?) has an impeller (10, 10?) integrally connected to a rotating drive shaft (2). The impeller is accommodated in a casing (3). Fluid (a) of a suction fluid passage (4) to be pumped flows into a center part (11) of the impeller. The fluid (b) is discharged from a peripheral portion (12) of the impeller by the effect of the centrifugal force of the rotating impeller, so that the fluid is delivered through a delivery fluid passage (5) outside of the casing. Many grooves (15) extending toward a peripheral edge of the impeller from the center part of the impeller are formed on the impeller. The groove opens on an outer circumferential surface (18) of the impeller, and causes strong recirculation vortices (R) to be formed in the vicinity of the peripheral edge of the impeller when the impeller rotates.
    Type: Grant
    Filed: January 14, 2009
    Date of Patent: June 25, 2013
    Assignee: National University Corporation Yokohama National University
    Inventors: Junichi Kurokawa, Shuusaku Kagawa
  • Publication number: 20100322771
    Abstract: The present invention provides a rotary-type fluid machine which enables practical and effective operation in an extremely low specific speed range. The rotary-type fluid machine (1, 1?) has an impeller (10, 10?) integrally connected to a rotating drive shaft (2). The impeller is accommodated in a casing (3). Fluid (a) of a suction fluid passage (4) to be pumped flows into a center part (11) of the impeller. The fluid (b) is discharged from a peripheral portion (12) of the impeller by the effect of the centrifugal force of the rotating impeller, so that the fluid is delivered through a delivery fluid passage (5) outside of the casing. Many grooves (15) extending toward a peripheral edge of the impeller from the center part of the impeller are formed on the impeller. The groove opens on an outer circumferential surface (18) of the impeller, and causes strong recirculation vortices (R) to be formed in the vicinity of the peripheral edge of the impeller when the impeller rotates.
    Type: Application
    Filed: January 14, 2009
    Publication date: December 23, 2010
    Applicant: National University Corporation Yokohama National University
    Inventors: Junichi Kurokawa, Shuusaku Kagawa
  • Patent number: 6736594
    Abstract: In an axial flow hydraulic machine, a plural number of grooves 5 are formed on an inner surface of a casing, directed into a pressure gradient direction, for connecting between an inlet side of an impeller 1 and an inside of blade residing region on the casing inner surface. With movement of movable members 6 provided on the casing inner surface, the grooves appear within the blade residing region in an unstable operation region, while the grooves cause no interference with the blades of the impeller in a stable operation region.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: May 18, 2004
    Assignees: Hitachi, Ltd., Junichi Kurokawa
    Inventors: Kouichi Irie, Tomoyoshi Okamura, Yoshio Anzai, Junichi Kurokawa
  • Patent number: 6582189
    Abstract: For improving characteristic uprising at the right-hand side of head-flow rate characteristic of a turbo machine, as well as for suppressing increase of vibration and/or noises thereof, a plurality of first grooves 24 in direction of gradient in pressure of fluid are formed on an inner flow surface of a casing, for connecting an inlet side of blades of an impeller and an area on the inner flow surface of the casing where the impeller blades reside in, over an inner circumference of the casing. Also, second grooves 25 in a circumferential direction are formed in an area on the inner flow surface of the casing where the impeller blades reside in, for communicating the first grooves in the circumferential direction of the casing.
    Type: Grant
    Filed: July 11, 2002
    Date of Patent: June 24, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kouichi Irie, Tomoyoshi Okamura, Akira Manabe, Junichi Kurokawa
  • Patent number: 6540482
    Abstract: A turbo-type machine, comprising a casing 2 storing an impeller within an inside thereof, and a plural number of grooves formed on an inner surface of the casing in a direction of pressure gradient of fluid, wherein the grooves 124 are provided from 80 to 150 pieces around a periphery on the inner surface of the casing, and a total width of the grooves all around the inner surface of the casing is from 30% to 50% of a peripheral length on the inner surface of the casing. Also, the area on cross-section of the groove 124 within an area where the blades exist is made larger than that of the groove outside where the blades exist, or openings 127 are drilled on a bottom surface of the grooves, each penetrating through thickness of the casing, or the groove is made in a two-layer structure in the direction of pressure gradient of fluid.
    Type: Grant
    Filed: March 20, 2001
    Date of Patent: April 1, 2003
    Assignees: Hitachi, Ltd.
    Inventors: Kouichi Irie, Tomoyoshi Okamura, Sumio Sudo, Junichi Kurokawa
  • Patent number: 6527509
    Abstract: A turbo machine comprising: an impeller having a plurality of blades therewith; a casing having a flow surface defined therein and being positioned with the impeller therein; and a plurality of grooves being formed in the flow surface of the casing, for connecting between an inlet side of said impeller and an area on the flow surface of the casing in which the blades of said impeller reside. Each groove has a length of at least part of which is oriented in an axial direction of the casing, a width measured in a circumferential direction, and a depth. The width of each groove is equal to or greater than the depth thereof.
    Type: Grant
    Filed: October 16, 2001
    Date of Patent: March 4, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Junichi Kurokawa, Hitoharu Kimura, Tomoyshi Okamura, Takahide Nagahara, Sumio Sudo, Akira Manabe, Norimitsu Kuwabara
  • Publication number: 20030031559
    Abstract: A turbo-type machine, comprising a casing 2 storing an impeller within an inside thereof, and a plural number of grooves formed on an inner surface of the casing in a direction of pressure gradient of fluid, wherein the grooves 124 are provided from 80 to 150 pieces around a periphery on the inner surface of the casing, and a total width of the grooves all around the inner surface of the casing is from 30% to 50% of a peripheral length on the inner surface of the casing. Also, the area on cross-section of the groove 124 within an area where the blades exist is made larger than that of the groove outside where the blades exist, or openings 127 are drilled on a bottom surface of the grooves, each penetrating through thickness of the casing, or the groove is made in a two-layer structure in the direction of pressure gradient of fluid.
    Type: Application
    Filed: March 20, 2001
    Publication date: February 13, 2003
    Inventors: Kouichi Irie, Tomoyoshi Okamura, Sumio Sudo, Junichi Kurokawa
  • Publication number: 20030002982
    Abstract: In an axial flow hydraulic machine, a plural number of grooves 5 are formed on an inner surface of a casing, directed into a pressure gradient direction, for connecting between an inlet side of an impeller 1 and an inside of blade residing region on the casing inner surface. With movement of movable members 6 provided on the casing inner surface, the grooves appear within the blade residing region in an unstable operation region, while the grooves cause no interference with the blades of the impeller in a stable operation region.
    Type: Application
    Filed: June 27, 2002
    Publication date: January 2, 2003
    Inventors: Kouichi Irie, Tomoyoshi Okamura, Yoshio Anzai, Junichi Kurokawa
  • Patent number: D508893
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: August 30, 2005
    Assignee: Shinko Electric Co., Ltd.
    Inventors: Kazumichi Kato, Toshio Miki, Hiroo Mike, Junichi Kurokawa
  • Patent number: D509794
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: September 20, 2005
    Assignee: Shinko Electric Co., Ltd.
    Inventors: Kazuo Okubo, Kazumichi Kato, Toshio Miki, Hiroo Mike, Junichi Kurokawa
  • Patent number: D511323
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: November 8, 2005
    Assignee: Shinko Electric Co., Ltd.
    Inventors: Kazumichi Kato, Toshio Miki, Hiroo Mike, Junichi Kurokawa
  • Patent number: D511495
    Type: Grant
    Filed: March 18, 2004
    Date of Patent: November 15, 2005
    Assignee: Shinko Electric Co., Ltd.
    Inventors: Kazuo Okubo, Kazumichi Kato, Toshio Miki, Hiroo Mike, Junichi Kurokawa
  • Patent number: D590340
    Type: Grant
    Filed: July 17, 2007
    Date of Patent: April 14, 2009
    Assignee: Shinko Electric Co., Ltd.
    Inventors: Fumio Sayama, Masami Morita, Hiroki Kataoka, Hiroaki Nishiono, Junichi Kurokawa, Tsuyoshi Muraoka
  • Patent number: D641699
    Type: Grant
    Filed: July 17, 2007
    Date of Patent: July 19, 2011
    Assignee: Shinko Electric Co., Ltd.
    Inventors: Fumio Sayama, Masami Morita, Hiroki Kataoka, Hiroaki Nishiono, Junichi Kurokawa, Tsuyoshi Muraoka