Patents by Inventor Hirokatsu Yamamoto

Hirokatsu Yamamoto 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: 11346296
    Abstract: Fuel injection control of an engine is executed by setting a required injection amount and an air-fuel ratio correction amount. When setting conditions are met, the air-fuel ratio correction amount is set for a corresponding region to which a current intake air amount or load ratio belongs among a plurality of regions into which the range of the intake air amount or the load ratio is divided such that a region of a larger intake air amount or a higher load ratio becomes wider than a region of a smaller intake air amount or a lower load ratio. When purge conditions are met, a purge control valve is controlled such that purge of supplying an evaporated fuel gas to an intake pipe is executed based on a required purge ratio.
    Type: Grant
    Filed: April 28, 2021
    Date of Patent: May 31, 2022
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masanao Idogawa, Takahiro Uchida, Masahiro Kachi, Reiko Goh, Hirokatsu Yamamoto
  • Patent number: 11325228
    Abstract: A rotary impact tool in one aspect of the present disclosure includes a motor, an impact mechanism, an impact detector, and a controller. The controller executes constant duty ratio control from when the motor is started until an impact is detected by the impact detector. The controller executes constant rotation speed control in response to detection of an impact by the impact detector.
    Type: Grant
    Filed: April 9, 2018
    Date of Patent: May 10, 2022
    Assignee: MAKITA CORPORATION
    Inventors: Takaaki Osada, Hirokatsu Yamamoto, Goshi Ishikawa, Kunihisa Shima
  • Patent number: 11286869
    Abstract: When a predetermined condition is satisfied, a flow rate ratio of a first passage flow rate to a second passage flow rate is estimated based on a throttle post pressure being a pressure on a downstream side of an intake pipe with respect to a throttle valve and an ejector pressure being a pressure of a suction port of an ejector. The first passage flow rate is a flow rate of an evaporated fuel gas flowing in a first purge passage. The second passage flow rate is a flow rate of the evaporated fuel gas flowing in a second purge passage. The first passage flow rate and the second passage flow rate are estimated based on the flow rate ratio and a valve passing flow rate being a flow rate of the evaporated fuel gas that passes through a purge control value.
    Type: Grant
    Filed: April 28, 2021
    Date of Patent: March 29, 2022
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masanao Idogawa, Takahiro Uchida, Masahiro Kachi, Reiko Goh, Hirokatsu Yamamoto
  • Patent number: 11248570
    Abstract: An engine apparatus includes an engine, a supercharger, an evaporated fuel treatment device, a controller and the engine apparatus is configured to determine a purge classification whether the evaporated fuel is a first purge in which the evaporated fuel flows dominantly in a first purge passage or a second purge in which the evaporated fuel flows dominantly in a second purge passage based on a relative ejector pressure that is a pressure of a suction port of the ejector and a value obtained by adding an offset amount based on a cross-sectional area of the second purge passage with respect to a cross-sectional area of the first purge passage to a pressure behind a throttle valve that is the pressure on a downstream side of the throttle valve of the intake pipe.
    Type: Grant
    Filed: February 15, 2021
    Date of Patent: February 15, 2022
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masanao Idogawa, Takahiro Uchida, Masahiro Kachi, Reiko Goh, Hirokatsu Yamamoto
  • Patent number: 11230983
    Abstract: A fuel injection valve is controlled by setting a required injection amount using a required load factor of an engine and a purge correction amount. A purge control valve is controlled using a driving duty based on a required purge ratio when a purge of supplying the evaporated fuel gas to an intake pipe is being executed. During execution of the purge, the purge concentration-related value is learned based on an air-fuel ratio deviation that is a deviation of an air-fuel ratio from a required air-fuel ratio. The certainty of the purge concentration-related value is estimated using a first counter that reflects a number of times of learning of the purge concentration-related value during a first purge and that does not reflect a number of times of learning of the purge concentration-related value during a second purge.
    Type: Grant
    Filed: April 23, 2021
    Date of Patent: January 25, 2022
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masanao Idogawa, Takahiro Uchida, Masahiro Kachi, Reiko Goh, Hirokatsu Yamamoto
  • Patent number: 11215146
    Abstract: When an execution condition for a purge of supplying evaporated fuel gas to an intake pipe is met, a required purge ratio is set within a range equal to or higher than a lower-limit purge ratio, and a purge control valve is controlled using a driving duty based on the required purge ratio. In this case, when the execution condition is continuously met, an ejector pressure is estimated based on a pressure difference between a supercharging pressure and a pre-compressor pressure, and on the driving duty, and the lower-limit purge ratio is set based on a post-throttle-valve pressure and on the ejector pressure. The value of the lower-limit purge ratio is set to zero immediately after the execution condition switches from being not met to being met.
    Type: Grant
    Filed: April 20, 2021
    Date of Patent: January 4, 2022
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masanao Idogawa, Takahiro Uchida, Masahiro Kachi, Reiko Goh, Hirokatsu Yamamoto
  • Publication number: 20210388784
    Abstract: When a predetermined condition is satisfied, a flow rate ratio of a first passage flow rate to a second passage flow rate is estimated based on a throttle post pressure being a pressure on a downstream side of an intake pipe with respect to a throttle valve and an ejector pressure being a pressure of a suction port of an ejector. The first passage flow rate is a flow rate of an evaporated fuel gas flowing in a first purge passage. The second passage flow rate is a flow rate of the evaporated fuel gas flowing in a second purge passage. The first passage flow rate and the second passage flow rate are estimated based on the flow rate ratio and a valve passing flow rate being a flow rate of the evaporated fuel gas that passes through a purge control value.
    Type: Application
    Filed: April 28, 2021
    Publication date: December 16, 2021
    Inventors: Masanao IDOGAWA, Takahiro UCHIDA, Masahiro KACHI, Reiko GOH, Hirokatsu YAMAMOTO
  • Publication number: 20210388782
    Abstract: A first arrival flow rate that is a flow rate of evaporative fuel gas that has arrived in a throttle downstream portion located downstream of a throttle valve in an intake pipe via a second purge passage after passing through a purge control valve is estimated based on a valve passage flow rate that is a flow rate of evaporative fuel gas that has passed through the purge control valve, and a first response delay in the flow of evaporative fuel gas through a route extending from the purge control valve to the throttle downstream portion via the second purge passage.
    Type: Application
    Filed: June 11, 2021
    Publication date: December 16, 2021
    Inventors: Masanao IDOGAWA, Takahiro UCHIDA, Masahiro KACHI, Reiko GOH, Hirokatsu YAMAMOTO
  • Publication number: 20210363929
    Abstract: During execution of a purge, a purge concentration-related value is learned based on an air-fuel ratio deviation that is a deviation of an air-fuel ratio detected by an air-fuel ratio sensor from a required air-fuel ratio. In this case, the purge concentration-related value is updated using an update amount with a smaller absolute value when the purge is a second purge of supplying evaporated fuel gas to an intake pipe through a second purge passage than when the purge is a first purge of supplying the evaporated fuel gas to the intake pipe through a first purge passage.
    Type: Application
    Filed: April 8, 2021
    Publication date: November 25, 2021
    Inventors: Masanao IDOGAWA, Takahiro UCHIDA, Masahiro KACHI, Reiko GOH, Hirokatsu YAMAMOTO
  • Publication number: 20210363944
    Abstract: When an execution condition for a purge of supplying evaporated fuel gas to an intake pipe is met, a required purge ratio is set within a range equal to or higher than a lower-limit purge ratio, and a purge control valve is controlled using a driving duty based on the required purge ratio. In this case, when the execution condition is continuously met, an ejector pressure is estimated based on a pressure difference between a supercharging pressure and a pre-compressor pressure, and on the driving duty, and the lower-limit purge ratio is set based on a post-throttle-valve pressure and on the ejector pressure. The value of the lower-limit purge ratio is set to zero immediately after the execution condition switches from being not met to being met.
    Type: Application
    Filed: April 20, 2021
    Publication date: November 25, 2021
    Inventors: Masanao IDOGAWA, Takahiro UCHIDA, Masahiro KACHI, Reiko GOH, Hirokatsu YAMAMOTO
  • Publication number: 20210363928
    Abstract: When first switching of switching from a first purge of supplying evaporated fuel gas to an intake pipe through a first purge passage to a second purge of supplying the evaporated fuel gas to the intake pipe through a second purge passage occurs and then second switching of switching from the second purge to the first purge occurs, a purge concentration-related value is corrected to a value closer to a first stored value that is the purge concentration-related value immediately before the first switching than to a second stored value that is the purge concentration-related value immediately before the second switching.
    Type: Application
    Filed: April 19, 2021
    Publication date: November 25, 2021
    Inventors: Masanao IDOGAWA, Takahiro UCHIDA, Masahiro KACHI, Reiko GOH, Hirokatsu YAMAMOTO
  • Publication number: 20210363930
    Abstract: A fuel injection valve is controlled by setting a required injection amount using a required load factor of an engine and a purge correction amount. A purge control valve is controlled using a driving duty based on a required purge ratio when a purge of supplying the evaporated fuel gas to an intake pipe is being executed. During execution of the purge, the purge concentration-related value is learned based on an air-fuel ratio deviation that is a deviation of an air-fuel ratio from a required air-fuel ratio. The certainty of the purge concentration-related value is estimated using a first counter that reflects a number of times of learning of the purge concentration-related value during a first purge and that does not reflect a number of times of learning of the purge concentration-related value during a second purge.
    Type: Application
    Filed: April 23, 2021
    Publication date: November 25, 2021
    Inventors: Masanao IDOGAWA, Takahiro UCHIDA, Masahiro KACHI, Reiko GOH, Hirokatsu YAMAMOTO
  • Publication number: 20210340927
    Abstract: Fuel injection control of an engine is executed by setting a required injection amount and an air-fuel ratio correction amount. When setting conditions are met, the air-fuel ratio correction amount is set for a corresponding region to which a current intake air amount or load ratio belongs among a plurality of regions into which the range of the intake air amount or the load ratio is divided such that a region of a larger intake air amount or a higher load ratio becomes wider than a region of a smaller intake air amount or a lower load ratio. When purge conditions are met, a purge control valve is controlled such that purge of supplying an evaporated fuel gas to an intake pipe is executed based on a required purge ratio.
    Type: Application
    Filed: April 28, 2021
    Publication date: November 4, 2021
    Inventors: Masanao IDOGAWA, Takahiro UCHIDA, Masahiro KACHI, Reiko GOH, Hirokatsu YAMAMOTO
  • Publication number: 20210317806
    Abstract: An engine apparatus includes an engine, a supercharger, an evaporated fuel treatment device, a controller and the engine apparatus is configured to determine a purge classification whether the evaporated fuel is a first purge in which the evaporated fuel flows dominantly in a first purge passage or a second purge in which the evaporated fuel flows dominantly in a second purge passage based on a relative ejector pressure that is a pressure of a suction port of the ejector and a value obtained by adding an offset amount based on a cross-sectional area of the second purge passage with respect to a cross-sectional area of the first purge passage to a pressure behind a throttle valve that is the pressure on a downstream side of the throttle valve of the intake pipe.
    Type: Application
    Filed: February 15, 2021
    Publication date: October 14, 2021
    Inventors: Masanao IDOGAWA, Takahiro UCHIDA, Masahiro KACHI, Reiko GOH, Hirokatsu YAMAMOTO
  • Patent number: 11084157
    Abstract: A work tool includes a motor, a driving mechanism, a housing, a handle, a detecting mechanism and an elastic support part. The detecting mechanism is configured to detect information corresponding to an operating state of the work tool. The elastic support part supports the detecting mechanism so as to be movable relative to the housing in at least two of a front-rear direction, an up-down direction and a left-right direction. The elastic support part includes at least one elastic member disposed between the detecting mechanism and the housing. The elastic support part has respectively different spring constants in the at least two directions.
    Type: Grant
    Filed: March 11, 2019
    Date of Patent: August 10, 2021
    Assignee: MAKITA CORPORATION
    Inventors: Kiyonobu Yoshikane, Yoshitaka Machida, Taro Hisano, Hirokatsu Yamamoto
  • Patent number: 11027867
    Abstract: A tying machine may include a twisting mechanism configured to twist a tying string. The twisting mechanism may include a twisting motor. The tying machine may be configured to obtain torque acting on the twisting motor as a twisting torque value, and stop the twisting motor when a predetermined tying completion condition is satisfied. The tying completion condition may include that an elapsed time since a rise in the twisting torque value was detected reaches a first predetermined time.
    Type: Grant
    Filed: December 17, 2018
    Date of Patent: June 8, 2021
    Assignee: MAKITA CORPORATION
    Inventors: Hirokatsu Yamamoto, Kunihisa Shima
  • Patent number: 10954947
    Abstract: A backpack-type blower according to one aspect of the present disclosure includes a plurality of fans, a plurality of DC power supplies and a backpack. The plurality of fans and the plurality of DC power supplies are mounted on the backpack. The backpack-type blower is configured to blow winds from the plurality of fans together.
    Type: Grant
    Filed: April 19, 2016
    Date of Patent: March 23, 2021
    Assignee: MAKITA CORPORATION
    Inventors: Hirokatsu Yamamoto, Yuki Kawai, Makoto Takahashi
  • Patent number: 10953524
    Abstract: An impact fastening tool may include a motor; a hammer configured to be rotationally driven by the motor; an anvil configured to be hit in a rotational direction by the hammer; a signal obtainer configured to obtain a variable signal which varies in accordance with a hit to the anvil by the hammer; and a seating determiner configured to determine whether or not a fastener has been seated based on the variable signal obtained by the signal obtainer, wherein the seating determiner is configured to determine whether or not the fastener has been seated based on a signal component of the variable signal obtained by the signal obtainer, the signal component corresponding to a predetermined reference frequency.
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: March 23, 2021
    Assignee: MAKITA CORPORATION
    Inventors: Masahiko Sako, Takaaki Osada, Hirokatsu Yamamoto
  • Patent number: 10953532
    Abstract: An electric power tool is configured to rotate an attachment about a Z-axis. The electric power tool includes a three-axes acceleration sensor and an acceleration detection circuit. The acceleration detection circuit calculates an angular acceleration about the Z-axis based on an input signal from the three-axes acceleration sensor. The acceleration detection circuit calculates a change in an angular velocity based on integrating the angular acceleration for a most recent period. The acceleration detection circuit determines a Z-axis angular velocity about the Z-axis, without adding a previous change in the angular velocity from before the most recent period, as equal to the change in angular velocity. The acceleration detection circuit detects a twisted-motion of the electric power tool based on the Z-axis angular velocity.
    Type: Grant
    Filed: October 3, 2017
    Date of Patent: March 23, 2021
    Assignee: MAKITA CORPORATION
    Inventors: Hikaru Sunabe, Hirokatsu Yamamoto, Takaaki Osada
  • Publication number: 20210078153
    Abstract: An electric working machine in one aspect of the present disclosure includes an output shaft, a motor, a housing, an acceleration detector, a twisted motion detector, a reference level changer, and a motor controller. The acceleration detector detects an acceleration of the housing in a circumferential direction of the output shaft. The twisted motion detector detects a twisted motion of the housing based on a reference level and the acceleration detected. The reference level determines that the housing is twisted. The reference level changer changes the reference level based on a rotating motion of the output shaft.
    Type: Application
    Filed: September 11, 2020
    Publication date: March 18, 2021
    Applicant: MAKITA CORPORATION
    Inventors: Hikaru SUNABE, Hirokatsu YAMAMOTO, Takaaki OSADA