Patents by Inventor Kenji Umayahara

Kenji Umayahara 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: 10427685
    Abstract: A vehicle capable of regenerative braking includes a motor that is configured to be driven with electric power. The vehicle selectively sets a drive mode of the vehicle in an accelerator-off state between an ordinary mode and a deceleration enhanced mode that decelerates the vehicle with higher deceleration force than deceleration force in the ordinary mode. The vehicle performs regenerative control of the motor in the ordinary mode or performs deceleration control of generating the deceleration force in the deceleration enhanced mode, in order to decelerate the vehicle in the set drive mode. When an accelerator stroke based on a driver's depression of an accelerator becomes higher than a cancellation threshold in the drive mode set to the deceleration enhanced mode, the cancellation threshold being determined in advance corresponding to the accelerator stroke being greater than zero, the vehicle changes the drive mode from the deceleration enhanced mode to the ordinary mode.
    Type: Grant
    Filed: June 1, 2017
    Date of Patent: October 1, 2019
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kenji Umayahara, Mitsuhiro Nada, Takuya Nakagami
  • Publication number: 20190267646
    Abstract: A fuel cell system includes: a fuel cell in which a plurality of cells are stacked; a voltage sensor configured to measure a cell voltage of the fuel cell; and a pressure sensor configured to measure an anode gas pressure in the fuel cell. When the cell voltage is lower than a predetermined threshold voltage, in a state in which an amount of supply of cathode gas to the fuel cell is secured, and a rate of decrease in the anode gas pressure is larger than a predetermined threshold rate, it is determined that a cross leak abnormality has occurred in the fuel cell.
    Type: Application
    Filed: January 3, 2019
    Publication date: August 29, 2019
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tomio YAMANAKA, Kenji UMAYAHARA
  • Publication number: 20190260045
    Abstract: When the fuel cell stack is operated in a state in which the air stoichiometric ratio is smaller than the predetermined value, the controller calculates the amount of retained water that has been retained in the cathode flow path of the fuel battery cell per fixed time in such a way that the calculated amount includes an extra amount therein, integrates the amount of retained water per fixed time that has been calculated in such a way that the calculated amount includes the extra amount therein, and executes air blow in the cathode flow path of the fuel battery cell when the integrated value of the amount of retained water becomes equal to or larger than the threshold.
    Type: Application
    Filed: January 3, 2019
    Publication date: August 22, 2019
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tomohiro OGAWA, Tomotaka ISHIKAWA, Tomio YAMANAKA, Ryoichi NANBA, Kenji UMAYAHARA
  • Patent number: 10291054
    Abstract: On a start of a fuel cell system, (i) when the temperature of a high-voltage secondary battery obtained from a temperature sensor is higher than a predetermined reference value, a controller of the fuel cell system is configured to set an output voltage on a step-down side of a DC-DC converter to a higher voltage than a voltage of a low-voltage secondary battery and subsequently start an FC auxiliary machine using electric power from the high-voltage secondary battery. (ii) When the temperature of the high-voltage secondary battery obtained from the temperature sensor is equal to or lower than the predetermined reference value, on the other hand, the controller of the fuel cell system is configured to set the output voltage on the step-down side of the DC-DC converter to a lower voltage than the voltage of the low-voltage secondary battery and subsequently start the FC auxiliary machine using the electric power from the high-voltage secondary battery.
    Type: Grant
    Filed: April 17, 2017
    Date of Patent: May 14, 2019
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Takao Watanabe, Akihiro Kamiya, Kenji Umayahara
  • Patent number: 10256654
    Abstract: On a start of a fuel cell system, (i) when the temperature of a high-voltage secondary battery obtained from a temperature sensor is higher than a predetermined reference value, a controller of the fuel cell system is configured to set an output voltage on a step-down side of a DC-DC converter to a higher voltage than a voltage of a low-voltage secondary battery and subsequently start an FC auxiliary machine using electric power from the high-voltage secondary battery. (ii) When the temperature of the high-voltage secondary battery obtained from the temperature sensor is equal to or lower than the predetermined reference value, on the other hand, the controller of the fuel cell system is configured to set the output voltage on the step-down side of the DC-DC converter to a lower voltage than the voltage of the low-voltage secondary battery and subsequently start the FC auxiliary machine using the electric power from the high-voltage secondary battery.
    Type: Grant
    Filed: April 17, 2017
    Date of Patent: April 9, 2019
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Takao Watanabe, Akihiro Kamiya, Kenji Umayahara
  • Patent number: 10128523
    Abstract: A fuel cell system is equipped with a fuel cell and a secondary battery. This fuel cell system is equipped with a recordation unit that records a charge-discharge history of the secondary battery, a prediction unit that predicts restriction on an output of the secondary battery based on the charge-discharge history recorded by the recordation unit, and an output control unit that starts power generation by the fuel cell prior to a timing of restriction on the output of the secondary battery, when the prediction unit predicts restriction on the output of the secondary battery and the fuel cell is in an intermittent operation state.
    Type: Grant
    Filed: May 2, 2017
    Date of Patent: November 13, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Akihiro Kamiya, Kenji Umayahara, Takao Watanabe, Tomoya Ogawa
  • Patent number: 10118493
    Abstract: A vehicle includes: a fuel cell that receives supply of fuel gas and generates electric power; a motor that is driven by the generated electric power of the fuel cell; an electric power consuming auxiliary machine; a mechanical brake; a secondary cell, and a deceleration control unit. The deceleration control unit limits the regenerative braking force to be obtained by the regenerative control, to an upper limit regenerative braking force corresponding to the maximum consumed electric power that the electric power consuming auxiliary machine is capable of consuming such that regenerative electric power associated with regenerative braking is consumed by the electric power consuming auxiliary machine, and when the electric power consuming auxiliary machine is incapable of consuming the regenerative electric power to the maximum consumed electric power, the residual regenerative electric power is consumed by charge of the secondary cell.
    Type: Grant
    Filed: November 13, 2015
    Date of Patent: November 6, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Mitsuhiro Nada, Kenji Umayahara, Takuya Nakagami
  • Patent number: 10115990
    Abstract: A fuel cell system installed in a vehicle includes a fuel cell that supplies power to a motor that drives the vehicle, a pump that supplies oxygen to the fuel cell, an accelerator position detector that detects an accelerator depression amount of the vehicle, and a controller that calculates required generated power of the fuel cell and required driving power of the pump, based on the accelerator depression amount. When a preset condition of causing a sharp drop in the calculated required generated power is satisfied, the controller calculates the required driving power in such a manner that a drop rate of the required driving power becomes higher than a drop rate of the calculated required generated power, sets a lower limit to the calculated required driving power, and drives the pump in accordance with the lower limit when the required driving power is lower than the lower limit.
    Type: Grant
    Filed: November 4, 2015
    Date of Patent: October 30, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yuji Kakeno, Kenji Umayahara, Mitsuhiro Nada
  • Patent number: 10103394
    Abstract: A fuel cell system is provided, which includes a fuel cell configured to generate power by a reaction of fuel gas and air, an air compressor configured to compress air and supplying the compressed air to the fuel cell, a controller configured to control operations of the fuel cell and the air compressor, and an exhaust system member configured to discharge off-gas and produced water from the fuel cell. When a first condition including a flow rate of air by the air compressor being greater than a first flow rate is satisfied, the controller increases a rotational speed of the air compressor to supply air at or more than a second flow rate that is greater than the first flow rate to the fuel cell, and to discharge water inside the fuel cell.
    Type: Grant
    Filed: September 30, 2015
    Date of Patent: October 16, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yasuo Matsubara, Kenji Umayahara
  • Patent number: 10099557
    Abstract: A vehicle driven by a motor includes: a secondary battery configured to supply an electric power to the motor; a power regeneration portion configured to supply, to the secondary battery, a regenerative electric power that is recovered at a time of braking the vehicle; a power storage amount detecting portion configured to detect a power storage amount of the secondary battery; and a controlling portion configured to control charging and discharging of the secondary battery. The controlling portion estimates a regenerative electric power, and estimates an expected power-storage increasing amount, so as to calculate a virtual power storage amount from a sum total of the expected power-storage increasing amount and an actual power storage amount. The controlling portion performs charging and discharging on the secondary battery based on the virtual power storage amount.
    Type: Grant
    Filed: October 28, 2015
    Date of Patent: October 16, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yasuo Matsubara, Kenji Umayahara
  • Patent number: 10071649
    Abstract: A method for controlling an external electric power supply system supplying electric power from a fuel cell and a secondary battery mounted on a vehicle to an external load, the method including controlling electric power from the fuel cell and the secondary battery such that externally supplied electric power supplied to the external load is equal to or less than supply allowed electric power, and setting the supply allowed electric power to be equal to or less than a smaller one of an upper limit value of electric power which the secondary battery is charged with set in accordance with a temperature, and an electric power storage amount of the secondary battery and an upper limit value of electric power discharged from the secondary battery set in accordance with the temperature and the electric power storage amount of the secondary battery.
    Type: Grant
    Filed: November 12, 2015
    Date of Patent: September 11, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yasuo Matsubara, Kenji Umayahara, Keigo Suematsu
  • Patent number: 10056626
    Abstract: A fuel cell system mounted in a vehicle includes a fuel cell supplying electric power to a motor driving the vehicle, a pump supplying oxygen to the fuel cell, an accelerator position detection unit detecting an accelerator depression amount of the vehicle, and a control unit calculating electric power required to be generated by the fuel cell and electric power required for driving of the pump based on the accelerator depression amount and controlling the pump based on the electric power required for the driving, in which the control unit calculates the electric power required for the driving such that a rate of increase in the electric power required for the driving exceeds a rate of increase in the electric power required to be generated when the calculated electric power required to be generated increases.
    Type: Grant
    Filed: November 12, 2015
    Date of Patent: August 21, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yuji Kakeno, Mitsuhiro Nada, Kenji Umayahara, Yutaka Tano
  • Patent number: 9970447
    Abstract: A fuel cell system includes an air compressor that supplies oxidant gas to a fuel cell installed in a fuel cell vehicle, a measured rotational speed acquirer that acquires a measured value of rotational speed of the air compressor, and a controller that calculates a rotational speed command value of the air compressor based on required generated power of the fuel cell, calculates a torque command value of the air compressor based on the calculated rotational speed command value and current rotational speed of the air compressor, and controls rotational speed of the air compressor based on the calculated torque command value. The controller estimates the current rotational speed of the air compressor baaed on the measured value of the rotational speed acquired by the measured rotational speed acquirer and a history of the calculated torque command value, and calculates the torque command value by using the estimated rotational speed.
    Type: Grant
    Filed: November 6, 2015
    Date of Patent: May 15, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kohei Oda, Kenji Umayahara
  • Patent number: 9905869
    Abstract: In the event that at least a portion of unit cells in a fuel cell stack have experienced a significant drop in voltage, the fuel cell system will execute a voltage recovery process allowing them to recover generating capability. In the voltage recovery process, a controller measures impedance of the fuel cell stack, and based on these measurements, determines the hydration condition of the electrolyte membrane inside the fuel cell. If, during the determination of hydration condition, the controller has determined that the hydration level is low, a current limiting process for temporarily limiting output of the fuel cell in order to recover generating capability will be triggered under more lenient conditions, as compared to if determined that the hydration level is high.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: February 27, 2018
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kenji Umayahara, Takeshi Maenaka, Atsushi Imai
  • Patent number: 9905866
    Abstract: A fuel cell system includes a fuel cell containing a unit cell with an anode and a cathode included therein, a hydrogen supply unit that supplies hydrogen gas to the anode, a circulation pump that supplies an anode exhaust gas containing hydrogen that has not been used for power generation by the fuel cell and is discharged from the anode, once again to the anode to circulate the anode exhaust gas, and a controller that controls supply quantity of the hydrogen gas by the hydrogen supply unit as well as rotating speed of the circulation pump. The controller drives the circulation pump so that the rotating speed of the circulation pump approaches an optimum rotating speed of the circulation pump at which a total hydrogen loss quantity becomes a minimum under a specified current value, the total hydrogen loss quantity being a sum of a hydrogen quantity corresponding to an electric power necessary for driving the circulation pump and a hydrogen quantity passing from anode side to cathode side of the fuel cell.
    Type: Grant
    Filed: November 11, 2015
    Date of Patent: February 27, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yasuo Matsubara, Kenji Umayahara
  • Patent number: 9889763
    Abstract: There is provided a control method of an external power supply system configured to supply power to the outside from a fuel cell and a secondary battery mounted on a vehicle. When a failure is detected in a sensor that measures an electric power supplied to the outside from an electric power line to which the fuel cell and the secondary battery are connectable, (a) if a decrease in a state of charge of the secondary battery is detected, external power supply is performed by increasing a generated power of the fuel cell so as to stop the decrease in the state of charge, and (b) if an increase in a state of charge of the secondary battery is detected, external power supply is performed by decreasing the generated power of the fuel cell so as to stop the increase in the state of charge.
    Type: Grant
    Filed: October 15, 2015
    Date of Patent: February 13, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yasuo Matsubara, Kenji Umayahara
  • Patent number: 9884567
    Abstract: In a vehicle including a fuel cell system, an electronic control unit is configured to perform first processing in which a rotation speed of an air pump is controlled based on a torque command value and a rotation speed command value, and to perform, in the first processing, at least one of second processing in which the torque command value is set to be larger than the calculated torque command value when at least one of values of an accelerator position, required electric power, and the rotation speed command value or a change rate thereof is increased by a prescribed first value or more, and third processing in which the torque command value is set to be smaller than the calculated torque command value when at least one of the values or the change rate thereof is decreased by a prescribed second value or more.
    Type: Grant
    Filed: November 12, 2015
    Date of Patent: February 6, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kohei Oda, Kenji Umayahara, Yuji Kakeno, Mitsuhiro Nada
  • Patent number: 9873351
    Abstract: A fuel cell system to be installed on a vehicle includes a fuel cell, a secondary battery, an SOC detector that detects a temperature and a state of charge of the secondary battery, an accelerator position detector that detects an accelerator depressed amount, and a controller that controls power to be generated by the fuel cell. The controller includes: a required generation power calculator that calculates required generation power based on the accelerator depressed amount and the temperature and the state of charge of the secondary battery; and a maximum required power calculator that calculates maximum required power based on the accelerator depressed amount and the temperature and the state of charge of the secondary battery. The maximum required power includes allowable charging power correlated with a maximum value of charging power.
    Type: Grant
    Filed: July 12, 2017
    Date of Patent: January 23, 2018
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Yuji Kakeno, Mitsuhiro Nada, Kenji Umayahara, Yusuke Nishida
  • Publication number: 20170373333
    Abstract: An MG-ECU obtains a rotational speed Na of an ACP. The MG-ECU transmits the obtained rotational speed (a PM reception rotational speed) Na of the ACP to a PM-ECU through communication. The PM-ECU obtains a rotational speed predicted value Np by adding a rotational speed change width Cvw to the PM reception rotational speed Na received from the delayed MG-ECU. A limit torque Tr12 is obtained through the use of the obtained rotational speed predicted value Np and an ACP permissible power level line L1.
    Type: Application
    Filed: June 22, 2017
    Publication date: December 28, 2017
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Ryo KAJIURA, Kenji UMAYAHARA
  • Patent number: 9853313
    Abstract: A fuel cell system that includes a fuel cell that generates electricity through an electrochemical reaction between a fuel gas and an oxidant gas, and a control portion that determines whether there is leakage of the fuel gas. The control portion has start means for starting the fuel cell by raising the voltage of the fuel cell from a starting voltage to an operation voltage that is lower than an open-circuit voltage, and leakage determination means for determining whether there is leakage of the fuel gas before the voltage of the fuel cell reaches the operation voltage when the fuel cell is started.
    Type: Grant
    Filed: March 18, 2010
    Date of Patent: December 26, 2017
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Michio Yoshida, Kenji Umayahara, Atsushi Imai