Patents by Inventor Naoki Mitsumata

Naoki Mitsumata 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: 10151400
    Abstract: An electromagnetic valve includes a driving portion, a valve body, and a valve element. The driving portion generates a magnetic attractive force according to an energization. The valve body has an orifice through which a fluid flows, and a valve seat around an opening portion of the orifice. The valve element displaces according to the magnetic attractive force and a fluid force that is applied from the fluid, to vary a passage area between the valve element and the valve seat. When the valve element is placed at a position separated farthest from the valve seat, the passage area between the valve element and the valve seat is less than or equal to a passage area of the orifice.
    Type: Grant
    Filed: January 31, 2014
    Date of Patent: December 11, 2018
    Assignee: DENSO CORPORATION
    Inventors: Katsuhiro Ichihashi, Fumiaki Arikawa, Naoki Mitsumata, Masahiro Watanabe
  • Patent number: 9297471
    Abstract: An armature chamber receives an armature and includes a first armature chamber, which is placed adjacent to one end surface of the armature and is communicated with a spring chamber, and a second armature chamber, which is placed adjacent to the other end surface of the armature, which is opposite from the one end surface of the armature. The armature includes a primary communication passage that communicates between the first armature chamber and the second armature chamber. An opening end of the primary communication passage, which opens on a side where the first armature chamber is located, is placed at a corresponding location of the armature, which is opposed to the spring chamber.
    Type: Grant
    Filed: May 16, 2013
    Date of Patent: March 29, 2016
    Assignees: DENSO CORPORATION, NIPPON SOKEN, INC.
    Inventors: Fumiaki Arikawa, Naoki Mitsumata
  • Patent number: 9046186
    Abstract: An electromagnetic valve includes a rod, an armature fixed to the rod, and a stopper that limits motion of the armature to one side in an axial direction of the rod. The armature has a rod hole through which a fixed portion of the rod extends to be fixed to the armature. The rod includes a flange portion that is located on the one side in the axial direction with reference to the fixed portion. The flange portion is larger than the fixed portion in a radial direction of the rod. The armature includes a contact portion adjacent to an opening of the rod hole that is open toward the one side in the axial direction, and the contact portion contacts the flange portion.
    Type: Grant
    Filed: December 19, 2012
    Date of Patent: June 2, 2015
    Assignee: DENSO CORPORATION
    Inventors: Naoki Mitsumata, Shigeru Nonoyama
  • Publication number: 20140217317
    Abstract: An electromagnetic valve includes a driving portion, a valve body, and a valve element. The driving portion generates a magnetic attractive force according to an energization. The valve body has an orifice through which a fluid flows, and a valve seat around an opening portion of the orifice. The valve element displaces according to the magnetic attractive force and a fluid force that is applied from the fluid, to vary a passage area between the valve element and the valve seat. When the valve element is placed at a position separated farthest from the valve seat, the passage area between the valve element and the valve seat is less than or equal to a passage area of the orifice.
    Type: Application
    Filed: January 31, 2014
    Publication date: August 7, 2014
    Applicant: DENSO CORPORATION
    Inventors: Katsuhiro ICHIHASHI, Fumiaki ARIKAWA, Naoki MITSUMATA, Masahiro WATANABE
  • Publication number: 20130306895
    Abstract: An armature chamber receives an armature and includes a first armature chamber, which is placed adjacent to one end surface of the armature and is communicated with a spring chamber, and a second armature chamber, which is placed adjacent to the other end surface of the armature, which is opposite from the one end surface of the armature. The armature includes a primary communication passage that communicates between the first armature chamber and the second armature chamber. An opening end of the primary communication passage, which opens on a side where the first armature chamber is located, is placed at a corresponding location of the armature, which is opposed to the spring chamber.
    Type: Application
    Filed: May 16, 2013
    Publication date: November 21, 2013
    Inventors: Fumiaki ARIKAWA, Naoki MITSUMATA
  • Patent number: 7712453
    Abstract: An object of the invention is to provide a depressurizing valve mounted to a common rail for a fuel injection device, in which a direction of a connector for the depressurizing valve can be adjusted, without affecting an air gap and a sealing performance. The depressurizing valve has a valve unit and a coil unit which is detachably assembled to the valve unit by a mounting member, such as a retaining nut. A valve housing has an inside space, which is fluid tightly separated into first and second spaces by a connecting member, which is fluid tightly connected to the valve housing and a stator core. A valve body and a spring are arranged in the first space for closing a flow control port. A cylindrical coil is accommodated in the second space, such that the coil is rotatable with respect to the valve housing.
    Type: Grant
    Filed: October 13, 2006
    Date of Patent: May 11, 2010
    Assignee: DENSO CORPORATION
    Inventors: Shigeru Nonoyama, Naoki Mitsumata, Fumiaki Murakami
  • Patent number: 7578494
    Abstract: A solenoid valve includes a coil, a stator core, a valve member, a coil spring, and a stopper. The coil provides a magnetic field when the coil is energized. The stator core includes a receiving bore, wherein the stator core generates a magnetic attractive force when the coil is energized. The valve member is attracted toward the stator core due to the magnetic attractive force generated by the stator core. The coil spring is received in the receiving bore of the stator core, wherein the coil spring biases the valve member in an opposite direction opposite from the stator core. The stopper positions the coil spring such that an outer peripheral surface of the coil spring is separated from an inner peripheral surface of the receiving bore.
    Type: Grant
    Filed: February 7, 2007
    Date of Patent: August 25, 2009
    Assignee: Denso Corporation
    Inventors: Naoki Mitsumata, Fumiaki Murakami, Shigeru Nonoyama
  • Patent number: 7552908
    Abstract: A solenoid drive apparatus for driving a driven member by a magnetic attractive force includes a tubular magnetic metallic body, a coil, a magnetic metallic plate, and a magnetic gasket. The tubular magnetic metallic body has an opening portion at one end. The coil is received in the body from the opening portion and provides a magnetic field when the coil is energized. The magnetic metallic plate closes the opening portion of the body. The magnetic gasket is held between the body and the plate.
    Type: Grant
    Filed: September 14, 2006
    Date of Patent: June 30, 2009
    Assignee: DENSO CORPORATION
    Inventors: Naoki Mitsumata, Fumiaki Murakami
  • Patent number: 7441546
    Abstract: A pushrod is slidably received in a slidably holding guide, which is formed separately from a valve body of a valve apparatus. A clearance is provided between an inner peripheral surface of a small diameter tube portion of the valve body and an outer peripheral surface of the guide. The clearance is provided to absorb deformation of the small diameter tube portion.
    Type: Grant
    Filed: July 20, 2006
    Date of Patent: October 28, 2008
    Assignee: Denso Corporation
    Inventors: Naoki Mitsumata, Fumiaki Murakami
  • Publication number: 20070200655
    Abstract: An electromagnetic actuator includes a cylindrical coil, a stator core disposed in the cylindrical coil, a plate attached to one axial end of the stator core and an armature positioned to face the other axial end of the stator core. Upon energizing the coil, the armature is attracted to the stator core against a biasing force of a spring disposed in an inner space of the stator core. A depressed portion is formed on the plate and/or the stator core to suppress a magnetic flux passing therethrough and to reduce an amount of leakage flux. The magnetic flux generated by the coil is effectively used to drive the armature, and thereby a response time of the actuator is shortened. In other words, the armature is quickly driven upon energizing the coil.
    Type: Application
    Filed: December 5, 2006
    Publication date: August 30, 2007
    Applicant: DENSO CORPORATION
    Inventors: Fumiaki Murakami, Shigeru Nonoyama, Naoki Mitsumata
  • Publication number: 20070181840
    Abstract: A solenoid valve includes a coil, a stator core, a valve member, a coil spring, and a stopper. The coil provides a magnetic field when the coil is energized. The stator core includes a receiving bore, wherein the stator core generates a magnetic attractive force when the coil is energized. The valve member is attracted toward the stator core due to the magnetic attractive force generated by the stator core. The coil spring is received in the receiving bore of the stator core, wherein the coil spring biases the valve member in an opposite direction opposite from the stator core. The stopper positions the coil spring such that an outer peripheral surface of the coil spring is separated from an inner peripheral surface of the receiving bore.
    Type: Application
    Filed: February 7, 2007
    Publication date: August 9, 2007
    Applicant: DENSO CORPORATION
    Inventors: Naoki Mitsumata, Fumiaki Murakami, Shigeru Nonoyama
  • Publication number: 20070084443
    Abstract: An object of the invention is to provide a depressurizing valve mounted to a common rail for a fuel injection device, in which a direction of a connector for the depressurizing valve can be adjusted, without affecting an air gap and a sealing performance. The depressurizing valve has a valve unit and a coil unit which is detachably assembled to the valve unit by a mounting member, such as a retaining nut. A valve housing has an inside space, which is fluid tightly separated into first and second spaces by a connecting member, which is fluid tightly connected to the valve housing and a stator core. A valve body and a spring are arranged in the first space for closing a flow control port. A cylindrical coil is accommodated in the second space, such that the coil is rotatable with respect to the valve housing.
    Type: Application
    Filed: October 13, 2006
    Publication date: April 19, 2007
    Applicant: DENSO CORPORATION
    Inventors: Shigeru Nonoyama, Naoki Mitsumata, Fumiaki Murakami
  • Publication number: 20070057221
    Abstract: A solenoid drive apparatus for driving a driven member by a magnetic attractive force includes a tubular magnetic metallic body, a coil, a magnetic metallic plate, and a magnetic gasket. The tubular magnetic metallic body has an opening portion at one end. The coil is received in the body from the opening portion and provides a magnetic field when the coil is energized. The magnetic metallic plate closes the opening portion of the body. The magnetic gasket is held between the body and the plate.
    Type: Application
    Filed: September 14, 2006
    Publication date: March 15, 2007
    Applicant: DENSO CORPORATION
    Inventors: Naoki Mitsumata, Fumiaki Murakami
  • Publication number: 20070034819
    Abstract: A pushrod is slidably received in a slidably holding guide, which is formed separately from a valve body of a valve apparatus. A clearance is provided between an inner peripheral surface of a small diameter tube portion of the valve body and an outer peripheral surface of the guide. The clearance is provided to absorb deformation of the small diameter tube portion.
    Type: Application
    Filed: July 20, 2006
    Publication date: February 15, 2007
    Applicant: DENSO CORPORATION
    Inventors: Naoki Mitsumata, Fumiaki Murakami