Patents by Inventor Ryohei Maruo

Ryohei Maruo 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: 20210339724
    Abstract: A stroke simulator is configured in such a manner that an elastic member disposed in a cylinder of the stroke simulator is restricted from being deformed in a radial direction of the cylinder.
    Type: Application
    Filed: August 5, 2019
    Publication date: November 4, 2021
    Inventors: Ryohei MARUO, Takahiro KAWAKAMI
  • Publication number: 20210221345
    Abstract: The present invention provides a hydraulic control apparatus and a brake system capable of preventing or cutting down an increase in a size around a master cylinder. One aspect of the present invention includes a first hydraulic unit, a second hydraulic unit, and a stroke simulator unit. The first hydraulic unit includes a first input port connected to a supply port of a master cylinder, a first connection fluid passage connected to the first input port, a first pump configured to discharge brake fluid to the first connection fluid passage, and a first output port connected to the first connection fluid passage. The second hydraulic unit includes a second input port connected to the first output port, a second connection fluid passage connected to the second input port, a second pump configured to discharge the brake fluid to the second connection fluid passage, and a second output port having one end side connected to the second connection fluid passage and the other end side connected to a wheel cylinder.
    Type: Application
    Filed: May 8, 2017
    Publication date: July 22, 2021
    Inventors: Ryohei MARUO, Chiharu NAKAZAWA
  • Publication number: 20200254989
    Abstract: Provided is a hydraulic pressure control device capable of improving ease of layout. The hydraulic pressure control device includes a stroke simulator unit and a hydraulic pressure unit. The stroke simulator unit includes a stroke simulator, a simulator connection liquid passage, and a simulator connection port. The stroke simulator is independent of a master cylinder configured to generate a hydraulic pressure through a brake pedal operation, and is configured to generate a reaction force against the brake pedal operation. The simulator connection liquid passage has one end side connected to the stroke simulator, and an opposite end side. The simulator connection port is provided on the opposite end side of the simulator connection liquid passage. The stroke simulator unit is mounted to the hydraulic pressure unit. The hydraulic pressure unit includes a unit connection port and a liquid passage.
    Type: Application
    Filed: October 24, 2016
    Publication date: August 13, 2020
    Inventors: Takahiro KAWAKAMI, Ryohei MARUO, Chiharu NAKAZAWA
  • Patent number: 10668909
    Abstract: Provided is a master cylinder unit including a simulator pressure chamber which communicates with a pressure chamber of a master cylinder and moves a simulator piston by means of an introduced fluid pressure; a biasing chamber in which a biasing mechanism biasing the simulator piston against a fluid pressure introduced into the simulator pressure chamber is disposed; a first seal member which partitions a simulator supply chamber, the simulator supply chamber, and the simulator pressure chamber communicating with a master supply chamber; and a second seal member which partitions the simulator supply chamber and the biasing chamber and allows a brake fluid to flow from the simulator supply chamber to the biasing chamber when a pressure difference occurs between the simulator supply chamber and the biasing chamber.
    Type: Grant
    Filed: July 25, 2016
    Date of Patent: June 2, 2020
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Naganori Koshimizu, Hiroshi Owada, Toshiya Oosawa, Ryohei Maruo
  • Patent number: 10562504
    Abstract: Provided is a master cylinder unit including a communication path that causes a master cylinder and a stroke simulator to communicate with each other. The stroke simulator includes a bottomed tube-shaped simulator piston and a simulator cylinder in which a simulator piston slides. The simulator piston is such that a bottom portion of the simulator cylinder and an opening portion of the simulator piston face each other. The communication path is open over an outer circumferential portion and an inner circumferential portion of the opening portion of the simulator piston, is connected to the bottom portion of the simulator cylinder, and is provided such that the communication path extends upward in a vertical direction from the bottom portion of the simulator cylinder as approaching to a pressure chamber.
    Type: Grant
    Filed: July 25, 2016
    Date of Patent: February 18, 2020
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Naganori Koshimizu, Hiroshi Owada, Chiharu Nakazawa, Ryohei Maruo
  • Publication number: 20190329748
    Abstract: An object of the present invention is to provide a hydraulic control apparatus capable of layout flexibility. A hydraulics control apparatus includes a second unit (a hydraulic unit) and a first unit (a stroke simulator unit). The second unit includes a housing including a brake fluid passage therein, a positive pressure fluid passage and a back-pressure fluid passage (a unit connection fluid passage) each having one end side connected to the brake fluid passage, a positive pressure port and a back-pressure port (a unit connection port) provided on a surface of the housing and connected to the other end sides of the positive pressure fluid passage and the back-pressure fluid passage, a pump (a hydraulic source) provided inside the housing and configured to generate a hydraulic pressure in each of wheel cylinders of a vehicle via the brake fluid passage, and a motor attached to a surface of the housing and configured to actuate the pump. The first unit includes a stroke simulator.
    Type: Application
    Filed: June 15, 2017
    Publication date: October 31, 2019
    Inventors: Takahiro KAWAKAMI, Ryohei MARUO, Chiharu NAKAZAWA
  • Publication number: 20190217834
    Abstract: Provided is a hydraulic control apparatus and a brake system capable of improving responsiveness in terms of increasing a pressure in a wheel cylinder. The hydraulic control apparatus includes a connection fluid passage connected to a wheel cylinder of a wheel, a first hydraulic source, and a second hydraulic source. The first hydraulic source includes a first discharge port connected to the connection fluid passage and a first intake port connected to a reservoir storing brake fluid therein. The second hydraulic source includes a second discharge port connected to the connection fluid passage and a second intake port connected to the reservoir.
    Type: Application
    Filed: May 8, 2017
    Publication date: July 18, 2019
    Inventors: Ryohei MARUO, Chiharu NAKAZAWA
  • Patent number: 10328919
    Abstract: A brake apparatus is provided which has applicability to a wide range of vehicles. The brake apparatus includes a master cylinder provided in such a manner that a piston is axially operable in a master cylinder housing, and a stroke simulator including a reaction force piston axially operable by brake fluid introduced into a stroke simulator housing. The master cylinder housing is fixed to the stroke simulator housing. The stroke simulator housing is positioned between the master cylinder housing and a fixation piece structured to fix the stroke simulator housing to the vehicle. The fixation piece is spaced from the master cylinder housing.
    Type: Grant
    Filed: May 23, 2014
    Date of Patent: June 25, 2019
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Masaki Misunou, Ryohei Maruo, Chiharu Nakazawa
  • Patent number: 10207691
    Abstract: A brake apparatus includes a brake operation member, a state detection unit, a cylinder, a first portion, an operation rod, a stepped piston, first, second, and third seal members, first and second pressure chambers, a hydraulic source, and first and second oil passages. The brake apparatus also includes a fluid amount control unit. The fluid amount control unit is configured to control an amount of the brake fluid to be supplied to the first pressure chamber and the second pressure chamber. The fluid amount control unit is also configured to increase the amount of the brake fluid to be supplied to the second pressure chamber when the detected state is equal to a preset pressure increase request.
    Type: Grant
    Filed: June 12, 2015
    Date of Patent: February 19, 2019
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Chiharu Nakazawa, Ryohei Maruo
  • Patent number: 10207690
    Abstract: An object of the present invention is to provide a brake apparatus that allows low-cost attachment of a stroke sensor that detects a stroke amount of a brake pedal. The brake apparatus is configured in such a manner that the stroke sensor that detects an amount of an axial stroke of a piston is disposed between one side surface of a master cylinder housing and one side surface of a valve housing, and an output of the stroke sensor is transmitted via a through-hole formed on the valve housing when being transmitted to a control unit attached to an opposite side surface-side of the valve housing.
    Type: Grant
    Filed: April 23, 2015
    Date of Patent: February 19, 2019
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Chiharu Nakazawa, Ryohei Maruo
  • Patent number: 10202108
    Abstract: A brake apparatus improved in mountability on a vehicle is provided. The apparatus includes a master cylinder 4 that generates hydraulic brake pressure by a driver's brake operation, and a stroke simulator 5 that creates an artificial operation reaction force of a brake operation member when the brake fluid flown out of the master cylinder 4 enters the stroke simulator 5. The master cylinder 4 and the stroke simulator 5 are integrally arranged to overlap each other in a perpendicular direction (as viewed from the perpendicular direction) when installed in the vehicle.
    Type: Grant
    Filed: May 21, 2014
    Date of Patent: February 12, 2019
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Masaki Misunou, Ryohei Maruo, Chiharu Nakazawa
  • Publication number: 20190039590
    Abstract: Provided are a brake apparatus, a brake system, and a master cylinder that can accurately detect a movement amount of a piston while reducing manufacturing cost. A brake apparatus includes a master cylinder housing including a cylinder therein, a piston provided inside the cylinder and movable in a direction of an axial line of the cylinder, a magnet provided, inside the cylinder, partially in a circumferential direction of the piston, which is a direction around the axial line, and configured to be displaced according to a movement of the piston, a detection portion provided on the master cylinder housing and configured to detect a movement amount of the piston, and a rotation restriction mechanism provided inside the cylinder and configured to restrict a movement of the magnet in the circumferential direction.
    Type: Application
    Filed: February 3, 2017
    Publication date: February 7, 2019
    Inventors: Ryohei MARUO, Chiharu NAKAZAWA, Hiroshi OWADA, Naganori KOSHIMIZU
  • Publication number: 20180265060
    Abstract: Provided is a braking device capable of improving ease of layout inside a housing. The braking device includes: a housing, a pump provided in the housing, a suction oil passage provided inside the housing, and connected to a suction part of the pump, and a reservoir provided inside the housing, having an opening for connection to an oil passage outside the housing on an outer surface of the housing. The suction oil passage open in the reservoir. Brake fluid is reserved in the reservoir.
    Type: Application
    Filed: August 16, 2016
    Publication date: September 20, 2018
    Inventors: Ryohei MARUO, Chiharu NAKAZAWA
  • Publication number: 20180245573
    Abstract: An object of the present invention is to provide a hydraulic control apparatus capable of further effectively preventing or reducing a vibration. A second unit includes a housing including fluid passages and the like provided therein and configured to be mounted on a vehicle, a rotational driving shaft provided inside the housing, and a plurality of pump portions configured to be activated by a rotation of the rotational driving shaft and disposed in a direction around a central axis of the rotational driving shaft inside the housing. The pump portions are provided in such a manner that the number of pump portions positioned on a vertically lower side is larger than the number of pump portions positioned on a vertically upper side with respect to the central axis of the rotational driving shaft with the housing mounted on the vehicle.
    Type: Application
    Filed: August 2, 2016
    Publication date: August 30, 2018
    Inventors: Ryohei MARUO, Chiharu NAKAZAWA
  • Publication number: 20180215361
    Abstract: Provided is a master cylinder unit including a communication path that causes a master cylinder and a stroke simulator to communicate with each other. The stroke simulator includes a bottomed tube-shaped simulator piston and a simulator cylinder in which a simulator piston slides. The simulator piston is such that a bottom portion of the simulator cylinder and an opening portion of the simulator piston face each other. The communication path is open over an outer circumferential portion and an inner circumferential portion of the opening portion of the simulator piston, is connected to the bottom portion of the simulator cylinder, and is provided such that the communication path extends upward in a vertical direction from the bottom portion of the simulator cylinder as approaching to a pressure chamber.
    Type: Application
    Filed: July 25, 2016
    Publication date: August 2, 2018
    Inventors: Naganori KOSHIMIZU, Hiroshi OWADA, Chiharu NAKAZAWA, Ryohei MARUO
  • Publication number: 20180201247
    Abstract: Provided is a master cylinder unit including a simulator pressure chamber which communicates with a pressure chamber of a master cylinder and moves a simulator piston by means of an introduced fluid pressure; a biasing chamber in which a biasing mechanism biasing the simulator piston against a fluid pressure introduced into the simulator pressure chamber is disposed; a first seal member which partitions a simulator supply chamber, the simulator supply chamber, and the simulator pressure chamber communicating with a master supply chamber; and a second seal member which partitions the simulator supply chamber and the biasing chamber and allows a brake fluid to flow from the simulator supply chamber to the biasing chamber when a pressure difference occurs between the simulator supply chamber and the biasing chamber.
    Type: Application
    Filed: July 25, 2016
    Publication date: July 19, 2018
    Inventors: Naganori KOSHIMIZU, Hiroshi OWADA, Toshiya OOSAWA, Ryohei MARUO
  • Publication number: 20180037203
    Abstract: An object of the present invention is to provide a hydraulic control apparatus and a brake system capable of preventing or cutting down a cost increase. According to one aspect of the present invention, a hydraulic control apparatus includes a hydraulic source provided inside a housing and configured to generate a hydraulic pressure in a hydraulic generation unit mounted on a wheel via an oil passage, a switching electromagnetic valve provided integrally in the housing and configured to be used to permit an inflow of brake fluid into a stroke simulator provided separately from the housing and configured to generate a reaction force of a brake pedal operation performed by a driver, and a control unit provided integrally in the housing and configured to be used to drive the hydraulic source and the switching electromagnetic valve.
    Type: Application
    Filed: February 3, 2016
    Publication date: February 8, 2018
    Inventors: Ryohei MARUO, Chiharu NAKAZAWA, Masaki MISUNO
  • Publication number: 20170349155
    Abstract: A brake unit (1) includes: a master cylinder (2) unit which is fixed to a vehicle body, and which includes a master cylinder (2b) that is received within a first housing (20), and that is arranged to be interlocked with a brake pedal; and a pump unit (3) which is arranged to be driven by a motor (3), and which includes a second housing (30) within which a pump arranged to increase a wheel cylinder pressure is received, the master cylinder unit (2) and the pump unit (3) being integrally fixed through a mount (6) which is an elastic member.
    Type: Application
    Filed: August 22, 2017
    Publication date: December 7, 2017
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Ryohei MARUO, Masayuki SAITO, Chiharu NAKAZAWA
  • Patent number: 9764723
    Abstract: A brake unit (1) includes: a master cylinder (2) unit which is fixed to a vehicle body, and which includes a master cylinder (2b) that is received within a first housing (20), and that is arranged to be interlocked with a brake pedal; and a pump unit (3) which is arranged to be driven by a motor (3), and which includes a second housing (30) within which a pump arranged to increase a wheel cylinder pressure is received, the master cylinder unit (2) and the pump unit (3) being integrally fixed through a mount (6) which is an elastic member.
    Type: Grant
    Filed: August 22, 2013
    Date of Patent: September 19, 2017
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Ryohei Maruo, Masayuki Saito, Chiharu Nakazawa
  • Publication number: 20170190328
    Abstract: An object of the present invention is to provide a brake apparatus that allows low-cost attachment of a stroke sensor that detects a stroke amount of a brake pedal. The brake apparatus is configured in such a manner that the stroke sensor that detects an amount of an axial stroke of a piston is disposed between one side surface of a master cylinder housing and one side surface of a valve housing, and an output of the stroke sensor is transmitted via a through-hole formed on the valve housing when being transmitted to a control unit attached to an opposite side surface-side of the valve housing.
    Type: Application
    Filed: April 23, 2015
    Publication date: July 6, 2017
    Inventors: Chiharu NAKAZAWA, Ryohei MARUO