Patents by Inventor Masaharu NAKAOKA

Masaharu NAKAOKA 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: 11149865
    Abstract: A discharge valve includes: a valve main body that slidably contacts an inner peripheral wall of a tubular portion; and a primary passage that is formed at the valve main body and is located between the valve main body and the inner peripheral wall of the tubular portion. A stopper includes: a stopper main body that is formed separately from the tubular portion while the stopper main body is located on a side of the discharge valve that is opposite to the discharge valve seat; a movement limit surface that is configured to limit movement of the discharge valve in a direction away from the discharge valve seat; and a secondary passage that is formed at the stopper main body.
    Type: Grant
    Filed: August 26, 2019
    Date of Patent: October 19, 2021
    Assignee: DENSO CORPORATION
    Inventor: Masaharu Nakaoka
  • Patent number: 11092112
    Abstract: A high-pressure pump is configured to pressurize fuel. The high-pressure pump includes a relief valve device that is placed in a relief passage, which has one end part connected to a discharge passage in a housing while another end part of the relief passage is configured to be communicated with a suction passage in the housing. The discharge passage is configured to conduct the fuel, which is pressurized in and discharged from a pressurizing chamber. The relief valve device is configured to enable or limit a flow of the fuel between one side of the relief passage, at which the discharge passage is located, and another side of the relief passage, which is opposite to the discharge passage, at a valve opening time or a valve closing time of the relief valve device.
    Type: Grant
    Filed: August 26, 2019
    Date of Patent: August 17, 2021
    Assignee: DENSO CORPORATION
    Inventors: Shinichiro Koshimoto, Masaharu Nakaoka
  • Patent number: 10927805
    Abstract: A valve member includes a specific range in which an overlap area that is an area in which a hole opening and a slide outer wall are overlapped with each other becomes gradually smaller and a minimum passage area that is a passage area between an intermediate chamber and a first hole being minimum becomes gradually larger as the valve member is moved in a direction away from a valve seat portion in a movable range in the axial direction.
    Type: Grant
    Filed: April 28, 2016
    Date of Patent: February 23, 2021
    Assignee: DENSO CORPORATION
    Inventors: Shinichiro Koshimoto, Kaoru Oda, Masaharu Nakaoka
  • Patent number: 10883463
    Abstract: A housing-includes a pressurizing chamber. A plunger is moved to increase and decrease a volume of the pressurizing chamber, so that the plunger can pressurize the fuel in the pressurizing chamber. A fuel chamber forming portion is placed on a radially outer side of the plunger and forms a fuel chamber that is communicated with the pressurizing chamber. A pulsation damper is placed in an inside of the fuel chamber and is operable to reduce pressure pulsation of the fuel in the fuel chamber. Fixable portions are placed on a radially outer side of the plunger while each of the fixable portions includes a receiving through-hole. The fixable portions are fixed to an engine with bolts, which are provided to correspond with the receiving through-holes, respectively. The fuel chamber forming portion is displaced from axes of the receiving through-holes.
    Type: Grant
    Filed: March 30, 2017
    Date of Patent: January 5, 2021
    Assignee: DENSO CORPORATION
    Inventors: Shinichiro Koshimoto, Masaharu Nakaoka, Shinobu Oikawa
  • Patent number: 10641219
    Abstract: The control device controls a fuel pump which repeatedly executes a discharge operation of pressurizing and discharging fuel in a pressurizing chamber with the pressurizing member. Furthermore, the control device includes: a pressurizing chamber temperature obtaining unit which obtains a pressurizing chamber temperature which is a temperature of the fuel in the pressurizing chamber; and a discharge amount control unit which increases a fuel discharge amount by one discharge operation of the fuel pump when the pressurizing chamber temperature obtained by the pressurizing chamber temperature obtaining unit is higher than a threshold value.
    Type: Grant
    Filed: December 26, 2016
    Date of Patent: May 5, 2020
    Assignee: DENSO CORPORATION
    Inventor: Masaharu Nakaoka
  • Patent number: 10598118
    Abstract: A high-pressure pump includes: a low-pressure chamber, into which low-pressure fuel discharged from a low-pressure pump flows; a pressurizing chamber, which pressurizes the low-low-pressure fuel; and a leak chamber, into which leaked fuel from the pressurizing chamber flows. The leaked fuel of the leak chamber is suctioned into and is pressurized in the pressurizing chamber together with the low-pressure fuel of the low-pressure chamber, so that the leaked fuel is discharged to an outside of the high-pressure pump as high-pressure fuel. Furthermore, a suction check valve, which is placed between the low-pressure chamber and the leak chamber, limits backflow of the leaked fuel of the leak chamber to the low-pressure chamber when the high-pressure pump does not supply the high-pressure fuel.
    Type: Grant
    Filed: November 26, 2015
    Date of Patent: March 24, 2020
    Assignee: DENSO CORPORATION
    Inventor: Masaharu Nakaoka
  • Publication number: 20190376606
    Abstract: A discharge valve includes: a valve main body that slidably contacts an inner peripheral wall of a tubular portion; and a primary passage that is formed at the valve main body and is located between the valve main body and the inner peripheral wall of the tubular portion. A stopper includes: a stopper main body that is formed separately from the tubular portion while the stopper main body is located on a side of the discharge valve that is opposite to the discharge valve seat; a movement limit surface that is configured to limit movement of the discharge valve in a direction away from the discharge valve seat; and a secondary passage that is formed at the stopper main body.
    Type: Application
    Filed: August 26, 2019
    Publication date: December 12, 2019
    Inventor: Masaharu NAKAOKA
  • Publication number: 20190376472
    Abstract: A high-pressure pump is configured to pressurize fuel. The high-pressure pump includes a relief valve device that is placed in a relief passage, which has one end part connected to a discharge passage in a housing while another end part of the relief passage is configured to be communicated with a suction passage in the housing. The discharge passage is configured to conduct the fuel, which is pressurized in and discharged from a pressurizing chamber. The relief valve device is configured to enable or limit a flow of the fuel between one side of the relief passage, at which the discharge passage is located, and another side of the relief passage, which is opposite to the discharge passage, at a valve opening time or a valve closing time of the relief valve device.
    Type: Application
    Filed: August 26, 2019
    Publication date: December 12, 2019
    Inventors: Shinichiro KOSHIMOTO, Masaharu NAKAOKA
  • Patent number: 10309393
    Abstract: A pump body of a high-pressure pump includes a pressure chamber formed in a deep portion of a cylinder. The pump body closes the pressure chamber on a side opposite to a plunger. The plunger reciprocates within the cylinder to vary a volume of the pressure chamber. The large-diameter portion provided at an end of the plunger on a side protruding to the pressure chamber has an outside diameter larger than an inside diameter of the cylinder and smaller than an inside diameter of the pressure chamber. In this case, the large-diameter portion is engaged with a step portion between the cylinder and the pressure chamber in a state before attachment of the high-pressure pump to an internal combustion engine. Accordingly, separation of the plunger from the cylinder is avoidable.
    Type: Grant
    Filed: December 22, 2015
    Date of Patent: June 4, 2019
    Assignee: DENSO CORPORATION
    Inventor: Masaharu Nakaoka
  • Publication number: 20190145364
    Abstract: A housing-includes a pressurizing chamber. A plunger is moved to increase and decrease a volume of the pressurizing chamber, so that the plunger can pressurize the fuel in the pressurizing chamber. A fuel chamber forming portion is placed on a radially outer side of the plunger and forms a fuel chamber that is communicated with the pressurizing chamber. A pulsation damper is placed in an inside of the fuel chamber and is operable to reduce pressure pulsation of the fuel in the fuel chamber. Fixable portions are placed on a radially outer side of the plunger while each of the fixable portions includes a receiving through-hole. The fixable portions are fixed to an engine with bolts, which are provided to correspond with the receiving through-holes, respectively. The fuel chamber forming portion is displaced from axes of the receiving through-holes.
    Type: Application
    Filed: March 30, 2017
    Publication date: May 16, 2019
    Inventors: Shinichiro KOSHIMOTO, Masaharu NAKAOKA, Shinobu OIKAWA
  • Publication number: 20190093611
    Abstract: The control device controls a fuel pump which repeatedly executes a discharge operation of pressurizing and discharging fuel in a pressurizing chamber with the pressurizing member. Furthermore, the control device includes: a pressurizing chamber temperature obtaining unit which obtains a pressurizing chamber temperature which is a temperature of the fuel in the pressurizing chamber; and a discharge amount control unit which increases a fuel discharge amount by one discharge operation of the fuel pump when the pressurizing chamber temperature obtained by the pressurizing chamber temperature obtaining unit is higher than a threshold value.
    Type: Application
    Filed: December 26, 2016
    Publication date: March 28, 2019
    Inventor: Masaharu NAKAOKA
  • Patent number: 10107241
    Abstract: A valve device is provided between a high-pressure pump and a fuel tank. A first valve member, an intermediate member and a second valve member are accommodated in a valve housing. The first valve member, which is arranged on a downstream side of the intermediate member, is biased by a first spring in a direction to a first valve seat formed in the intermediate member. The second valve member, which is arranged on an upstream side of the intermediate member, is biased by a second spring in a direction to a second valve seat formed in the intermediate member. When the first valve member is separated from the first valve seat, fuel flows in a forward direction from an upstream-side fuel passage to a downstream-side fuel passage. When the second valve member is separated from the second valve seat, the fuel flows in a reverse direction.
    Type: Grant
    Filed: June 16, 2015
    Date of Patent: October 23, 2018
    Assignee: DENSO CORPORATION
    Inventor: Masaharu Nakaoka
  • Publication number: 20180087481
    Abstract: A valve member includes a specific range in which an overlap area that is an area in which a hole opening and a slide outer wall are overlapped with each other becomes gradually smaller and a minimum passage area that is a passage area between an intermediate chamber and a first hole being minimum becomes gradually larger as the valve member is moved in a direction away from a valve seat portion in a movable range in the axial direction.
    Type: Application
    Filed: April 28, 2016
    Publication date: March 29, 2018
    Inventors: Shinichiro KOSHIMOTO, Kaoru ODA, Masaharu NAKAOKA
  • Publication number: 20180010562
    Abstract: A plunger of a high-pressure pump is provided reciprocatably on an inner side of a cylinder. A holder disposed on an opposite side of the cylinder from a pressurizing chamber includes a large tubular portion that provides a predetermined space between the large tubular portion and an outer wall of the plunger, and a small tubular portion that is disposed on an opposite side of the large tubular portion from the cylinder. A pin inserted into a hole of the plunger at a position corresponding to the large tubular portion protrudes radially outward from the outer wall of the plunger and is accommodated in a space on an inner side of the large tubular portion.
    Type: Application
    Filed: January 13, 2016
    Publication date: January 11, 2018
    Inventors: Shinobu OIKAWA, Masaharu NAKAOKA
  • Publication number: 20180010602
    Abstract: A pump body of a high-pressure pump includes a pressure chamber formed in a deep portion of a cylinder. The pump body closes the pressure chamber on a side opposite to a plunger. The plunger reciprocates within the cylinder to vary a volume of the pressure chamber. The large-diameter portion provided at an end of the plunger on a side protruding to the pressure chamber has an outside diameter larger than an inside diameter of the cylinder and smaller than an inside diameter of the pressure chamber. In this case, the large-diameter portion is engaged with a step portion between the cylinder and the pressure chamber in a state before attachment of the high-pressure pump to an internal combustion engine. Accordingly, separation of the plunger from the cylinder is avoidable.
    Type: Application
    Filed: December 22, 2015
    Publication date: January 11, 2018
    Inventor: Masaharu NAKAOKA
  • Publication number: 20180003138
    Abstract: A pump body of a high-pressure pump includes a pressure chamber formed in a deep portion of a cylinder. A plunger reciprocates within the cylinder to vary a volume of the pressure chamber. A discharge path and a supply path are formed in the pump body and extend in a radial direction of the cylinder from the pressure chamber. A pin provided at an end of the plunger in the pressure chamber protrudes in one radial direction of the plunger to the outside of an inner circumference of the cylinder. In this case, the pin is engaged with a step portion between the cylinder and the pressure chamber in a state before attachment of the high-pressure pump to an internal combustion engine. Accordingly, separation of the plunger from the cylinder is avoidable.
    Type: Application
    Filed: December 22, 2015
    Publication date: January 4, 2018
    Inventor: Masaharu NAKAOKA
  • Publication number: 20170306880
    Abstract: A high-pressure pump includes: a low-pressure chamber, into which low-pressure fuel discharged from a low-pressure pump flows; a pressurizing chamber, which pressurizes the low-low-pressure fuel; and a leak chamber, into which leaked fuel from the pressurizing chamber flows. The leaked fuel of the leak chamber is suctioned into and is pressurized in the pressurizing chamber together with the low-pressure fuel of the low-pressure chamber, so that the leaked fuel is discharged to an outside of the high-pressure pump as high-pressure fuel. Furthermore, a suction check valve, which is placed between the low-pressure chamber and the leak chamber, limits backflow of the leaked fuel of the leak chamber to the low-pressure chamber when the high-pressure pump does not supply the high-pressure fuel.
    Type: Application
    Filed: November 26, 2015
    Publication date: October 26, 2017
    Inventor: Masaharu NAKAOKA
  • Publication number: 20150361935
    Abstract: A valve device is provided between a high-pressure pump and a fuel tank. A first valve member, an intermediate member and a second valve member are accommodated in a valve housing. The first valve member, which is arranged on a downstream side of the intermediate member, is biased by a first spring in a direction to a first valve seat formed in the intermediate member. The second valve member, which is arranged on an upstream side of the intermediate member, is biased by a second spring in a direction to a second valve seat formed in the intermediate member. When the first valve member is separated from the first valve seat, fuel flows in a forward direction from an upstream-side fuel passage to a downstream-side fuel passage. When the second valve member is separated from the second valve seat, the fuel flows in a reverse direction.
    Type: Application
    Filed: June 16, 2015
    Publication date: December 17, 2015
    Inventor: Masaharu NAKAOKA