Patents by Inventor Keigo Suematsu

Keigo Suematsu 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: 8916307
    Abstract: The degree of dryness in a fuel cell can be judged more accurately. A system has: an impedance calculation part that calculates an impedance of a fuel cell, extracts from the calculated impedance a high-frequency impedance which is an impedance in a high frequency range and a low-frequency impedance which is an impedance in a low frequency range, and subtracts the high-frequency impedance from the low-frequency impedance to calculate a differential impedance; a water content calculation part that calculates the water content of an electrolyte membrane using the high-frequency impedance and calculates the water content of a catalyst layer using the differential impedance; and a water content control part that performs water content recovery processing to increase the water content of the catalyst layer if the water content of the catalyst layer is smaller than a predetermined water content.
    Type: Grant
    Filed: January 5, 2010
    Date of Patent: December 23, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Keigo Suematsu
  • Publication number: 20140342260
    Abstract: A fuel cell vehicle air-conditioning apparatus includes: a cooling system that adjusts a temperature of a fuel cell; a waste heat collection unit that collects at least a part of waste heat from the fuel cell and uses the collected waste heat to heat a cabin interior of the fuel cell vehicle; and a heat creation unit that creates heat for heating the fuel cell vehicle. The fuel cell vehicle air-conditioning apparatus calculates a fuel consumption amount required for the fuel cell to generate a total power generation amount, which is a sum of a heating power generation amount and a travel power generation amount, calculates an optimum temperature, which is a temperature of the fuel cell at which the fuel consumption amount reaches a minimum, and controls the cooling system such that the temperature of the fuel cell reaches the optimum temperature.
    Type: Application
    Filed: November 28, 2012
    Publication date: November 20, 2014
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Takashi Koyama, Yuichi Sakajo, Keigo Suematsu
  • Patent number: 8871392
    Abstract: A fuel cell system includes a hydrogen path for supplying odorant-added hydrogen to the fuel cell, an estimating unit to estimate the depositing of the odorant in the fuel cell, and control unit to heat the fuel cell up to a temperature at which at least part of the odorant deposited in the fuel cell evaporates when the depositing of the odorant is estimated.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: October 28, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Nobuo Watanabe, Keigo Suematsu, Tatsuaki Yokoyama, Katsuhiko Hirose, Atsushi Matsuba
  • Publication number: 20140295302
    Abstract: In a fuel cell monitoring device, a gas-diffusion resistance calculation section calculates a gas-diffusion resistance Rtotal indicating a difficulty of diffusing reaction gas to a catalyst layer in a fuel cell based on a gas reaction resistance Rct calculated by a resistance calculation section. A second diffusion resistance calculation section calculates a second diffusion resistance Rdry varying depending on a dried-up in the fuel cell based on a proton transfer resistance Rmem calculated by the resistance calculation section. A first diffusion resistance calculation section calculates a first diffusion resistance Rwet varying depending on a flooding in the fuel cell by subtracting the second diffusion resistance Rdry from the gas-diffusion resistance Rtotal. A water content calculation section calculates a water content of the fuel cell based on the first diffusion resistance. A recovery control section adjusts the water content in the fuel cell based on the calculated water content.
    Type: Application
    Filed: April 1, 2014
    Publication date: October 2, 2014
    Applicants: Denso Corporation, Toyota Jidosha Kabushiki Kaisha, Nippon Soken, Inc.
    Inventors: Yuji Ishikawa, Ikuyasu Kato, Takashi Yamada, Yuuichi Sakajoh, Keigo Suematsu
  • Patent number: 8790834
    Abstract: A gas-supply passage (6) via which anode gas is supplied to a fuel cell unit (2) and a gas-discharge passage (12) via which anode gas is discharged from the fuel cell unit (2) are connected via a communication passage (30). Circulation pump (32) switches the communication state of the communication passage between a closed state and an opened state. Circulation pump (32) causes a gas flow from the gas-discharge passage to the gas-supply passage when the communication passage (30) is in the opened state. The communication passage (30) is normally closed, and it is opened when a predetermined condition related to the operation state of the fuel cell unit (2) is satisfied.
    Type: Grant
    Filed: April 11, 2008
    Date of Patent: July 29, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Keigo Suematsu
  • Patent number: 8746274
    Abstract: Disclosed is a hydrogen supply apparatus which can mix an odorant with hydrogen gas even at a low temperature and can detect the leakage of the hydrogen gas. The apparatus comprises a gas storage means for storing hydrogen gas therein, an odorant-addition means for adding an odorant to the hydrogen gas fed from the gas storage means, and a temperature control means for controlling the temperature of at least one of the hydrogen gas stored in the gas storage means, the hydrogen gas fed from the gas storage means and the odorant.
    Type: Grant
    Filed: March 8, 2013
    Date of Patent: June 10, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Takahide Izutani, Tatsuaki Yokoyama, Syuuji Hirakata, Osamu Yumita, Hiroshi Fujitani, Keigo Suematsu, Masaaki Matsusue, Nobuo Watanabe, Katsuhiko Oshikawa, Katsuhiko Hirose, Takumi Kuwahara, Atsushi Matsuba
  • Patent number: 8728672
    Abstract: The moisture state of a fuel cell is determined without causing any variation in the supply state of the reactant gas to be supplied to the fuel cell. An output current control section temporarily performs a current sweep while maintaining the amount of oxidant gas to be supplied to the fuel cell. A resistance component calculation section calculates the resistance component in the fuel cell by using an output current value and an output voltage value of the fuel cell being that of when the current sweep is temporarily performed. A moisture content calculation section calculates the moisture content in the fuel cell by using the resistance component. A moisture content determination section determines whether or not the moisture content is equal to or lower than a dry state threshold value. A moisture content increasing processing section performs a moisture content increasing process when the moisture content is equal to or lower than the dry state threshold value.
    Type: Grant
    Filed: May 14, 2009
    Date of Patent: May 20, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Tomotaka Ishikawa, Keigo Suematsu, Nobuo Watanabe
  • Patent number: 8652699
    Abstract: This fuel cell system is for suppressing a backflow of water from an exhaust pipe outlet that discharges a reactant-off gas, without decreasing the performance and fuel consumption of a fuel cell, the exhaust pipe being configured to switch between a main discharge pipe and a sub discharge pipe by a switching means to discharge the reactant-off gas. The sub discharge pipe includes a rising gradient portion formed to incline upwards above a gradient of the main discharge pipe and a falling gradient portion formed to incline downwards at the downstream of the rising gradient portion. The switching valve switches to allow the reactant-off gas to be discharged from the main discharge pipe if an amount of reactant-off gas to be discharged is equal to or above a threshold value of an amount of discharge, and allow the reactant-off gas to be discharged from the sub discharge pipe if the amount of reactant-off gas to be discharged is below the threshold value of the amount of discharge.
    Type: Grant
    Filed: October 23, 2009
    Date of Patent: February 18, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Keigo Suematsu, Tomotaka Ishikawa, Yuichi Sakajo
  • Patent number: 8637201
    Abstract: A cooling system is provided.
    Type: Grant
    Filed: January 7, 2011
    Date of Patent: January 28, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Keigo Suematsu, Yuichi Sakajo, Masanori Uehara, Takashi Koyama
  • Publication number: 20130289813
    Abstract: An exhaust state control device for a fuel cell for a mobile unit includes an exhaust gas temperature sensor (17) that measures the temperature of exhaust gas in a discharge passage that discharges the exhaust gas from the main body of the fuel cell, and an ambient temperature sensor (19A) that measures the temperature of ambient air to which exhaust gas is to be discharged. If, based on the difference between the exhaust gas temperature and the ambient temperature, it is determined that white smoke is generated, it is determined whether a condition to reduce white smoke is satisfied. When a first condition is satisfied, a process to reduce white smoke is activated. When a second condition, which requires further reduction of white smoke than under the first condition, is satisfied, a process to suppress the generation of white smoke is activated.
    Type: Application
    Filed: April 4, 2013
    Publication date: October 31, 2013
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hiromi TANAKA, Keigo SUEMATSU, Takahide IZUTANI
  • Patent number: 8563191
    Abstract: A fuel cell system according to one aspect of the invention is operated in an ordinary mode and in a gas leakage detection mode. The fuel cell system includes fuel cells, a fuel gas supplier configured to supply a fuel gas to the fuel cells, a shutoff valve provided in a flow path for leading a flow of the fuel gas supply from the fuel gas supplier to the fuel cells and configured to shut off the fuel gas supply, and a variable pressure regulator provided in the flow path between the shutoff valve and the fuel cells to regulate a pressure of the fuel gas in a downstream in a flow direction of the fuel gas supply to a variable pressure value. In the ordinary mode, the fuel cell system sets the pressure value of the variable pressure regulator to an ordinary power generation pressure value for ordinary power generation.
    Type: Grant
    Filed: July 26, 2006
    Date of Patent: October 22, 2013
    Assignee: Totota Jidosha Kabushiki Kaisha
    Inventors: Koji Katano, Keigo Suematsu, Nobuhiro Tomosada
  • Publication number: 20130189593
    Abstract: Disclosed is a hydrogen supply apparatus which can mix an odorant with hydrogen gas even at a low temperature and can detect the leakage of the hydrogen gas. The apparatus comprises a gas storage means for storing hydrogen gas therein, an odorant-addition means for adding an odorant to the hydrogen gas fed from the gas storage means, and a temperature control means for controlling the temperature of at least one of the hydrogen gas stored in the gas storage means, the hydrogen gas fed from the gas storage means and the odorant.
    Type: Application
    Filed: March 8, 2013
    Publication date: July 25, 2013
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Takahide IZUTANI, Tatsuaki YOKOYAMA, Syuuji HIRAKATA, Osamu YUMITA, Hiroshi FUJITANI, Keigo SUEMATSU, Masaaki MATSUSUE, Nobuo WATANABE, Katsuhiko OSHIKAWA, Katsuhiko HIROSE, Takumi KUWAHARA, Atsushi MATSUBA
  • Patent number: 8486577
    Abstract: In a fuel cell system of the invention, a hydrogen leakage detection process closes a shutoff valve, which shuts off a supply of hydrogen from a hydrogen supply unit into a hydrogen supply flow path, and opens a pressure regulator, which reduces a pressure of hydrogen in the hydrogen supply flow path, so as to keep the hydrogen supply flow path in a state with no pressure regulation and make the fuel cell system in a leakage detectable state. In this leakage detectable state, the hydrogen leakage detection process measures at least one of a pressure and a flow rate as a state quantity of hydrogen in the hydrogen supply flow path that feeds the supply of hydrogen to fuel cells. The hydrogen leakage detection process analyzes a detected behavior of the state quantity in the leakage detectable process and specifies the occurrence of a hydrogen leakage in the downstream of the hydrogen supply unit.
    Type: Grant
    Filed: July 26, 2006
    Date of Patent: July 16, 2013
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Keigo Suematsu, Tatsuaki Yokoyama, Koji Katano, Nobuhiro Tomosada
  • Publication number: 20130065091
    Abstract: A fuel cell system includes: a fuel cell; a secondary cell that receives and stores surplus power by which output of the fuel cell is greater than power demanded of the system if the output is so, and that compensates for shortfall by which the output of the fuel cell is less than the power demanded of the system if the output is so; a voltage measurement portion that measures voltage of the fuel cell; a current measurement portion that measures current of the fuel cell; and a control portion that performs a control such that the voltage of the fuel cell does not exceed or equal a pre-set high-potential avoidance voltage. If a current-voltage characteristic of the fuel cell declines by at least a pre-determined amount from an early-period level, the control portion re-sets the high-potential avoidance voltage to a value that is smaller than an early-period set value.
    Type: Application
    Filed: February 24, 2011
    Publication date: March 14, 2013
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tomotaka Ishikawa, Hironori Noto, Keigo Suematsu, Koichiro Yamashita
  • Publication number: 20120247746
    Abstract: The vehicle control apparatus configured to control a vehicle includes a fuel cell configured to supply electric power to the vehicle; an air conditioning mechanism having a heater core; a first medium circuit; a radiator installed in the first medium circuit; a bypass circuit formed in the first medium circuit to make a bypass flow of the cooling medium bypassing the radiator; a regulation valve installed in the first medium circuit to regulate a ratio of a flow rate of the cooling medium going through the radiator to a flow rate of the cooling medium going through the bypass circuit; a second medium circuit; a cooling medium circulation pump installed in at least one of the first medium circuit and the second medium circuit; a temperature acquisition module; a warm-up controller; and a state switchover structure.
    Type: Application
    Filed: August 25, 2010
    Publication date: October 4, 2012
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Yuichi Sakajo, Keigo Suematsu, Yoshiaki Naganuma, Masanori Uehara, Takashi Koyama
  • Publication number: 20120214079
    Abstract: This fuel cell system is for suppressing a backflow of water from an exhaust pipe outlet that discharges a reactant-off gas, without decreasing the performance and fuel consumption of a fuel cell, the exhaust pipe being configured to switch between a main discharge pipe and a sub discharge pipe by a switching means to discharge the reactant-off gas. The sub discharge pipe includes a rising gradient portion formed to incline upwards above a gradient of the main discharge pipe and a falling gradient portion formed to incline downwards at the downstream of the rising gradient portion. The switching valve switches to allow the reactant-off gas to be discharged from the main discharge pipe if an amount of reactant-off gas to be discharged is equal to or above a threshold value of an amount of discharge, and allow the reactant-off gas to be discharged from the sub discharge pipe if the amount of reactant-off gas to be discharged is below the threshold value of the amount of discharge.
    Type: Application
    Filed: October 23, 2009
    Publication date: August 23, 2012
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Keigo Suematsu, Tomotaka Ishikawa, Yuichi Sakajo
  • Patent number: 8232019
    Abstract: The present invention provides a technology related to a fuel cell system capable of adjusting a discharge amount of an odorant discharged to an outside of a moving body according to a state of the moving body. The fuel cell system mounted to a moving body includes: a fuel cell which generates electric power by electrochemically reacting a hydrogen gas with an oxidation gas; and a adjusting portion which adjusts an amount of an odorant to be discharged to an outside of the moving body according to a state of the moving body, the odorant being included in an anode off-gas discharged from an anode side of the fuel cell.
    Type: Grant
    Filed: November 4, 2010
    Date of Patent: July 31, 2012
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Keigo Suematsu, Tatsuaki Yokoyama, Shuji Hirakata, Takahide Izutani, Atsushi Matsuba, Katsuhiko Oshikawa
  • Publication number: 20120100445
    Abstract: The invention is provided to reliably restore generated voltage that has declined due to clogging of water in a fuel cell stack. A method of operating a fuel cell system having a fuel cell stack that generates electricity through an electrochemical reaction between a fuel gas including hydrogen gas and an oxidation gas, wherein when a generated voltage of the fuel cell stack declines, the water-in-cell content of the fuel cell stack is adjusted so that a variation in cell pressure loss in the fuel cell stack decreases based on a characteristic curve of the water-in-cell content of the fuel cell stack and the cell pressure loss of the fuel cell stack.
    Type: Application
    Filed: July 9, 2009
    Publication date: April 26, 2012
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Yoshiaki Naganuma, Keigo Suematsu, Tomotaka Ishikawa, Hiroyuki Katsuda
  • Publication number: 20120058404
    Abstract: The moisture state of a fuel cell is determined without causing any variation in the supply state of the reactant gas to be supplied to the fuel cell. An output current control section [[71]] temporarily performs a current sweep while maintaining the amount of oxidant gas to be supplied to the fuel cell. A resistance component calculation section [[72b]] calculates the resistance component in the fuel cell by using an output current value and an output voltage value of the fuel cell being that of when the current sweep is temporarily performed. A moisture content calculation section [[72c]] calculates the moisture content in the fuel cell by using the resistance component. A moisture content determination section [[72d]] determines whether or not the moisture content is equal to or lower than a dry state threshold value. A moisture content increasing processing section [[73]] performs a moisture content increasing process when the moisture content is equal to or lower than the dry state threshold value.
    Type: Application
    Filed: May 14, 2009
    Publication date: March 8, 2012
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Tomotaka Ishikawa, Keigo Suematsu, Nobuo Watanabe
  • Publication number: 20120015263
    Abstract: In order to cause a plurality of cells in a fuel cell to be recovered to a desired humidity state, it is configured to determine that the cells present a mixture of dry and overly humid states in the case where a predetermined condition is satisfied, and in the case where it is determined that the cells present the mixture, humidifying control is carried out to cause all the cells to attain the overly humid state, and thereafter, drying control is carried out to dry all the cells, to thereby cause the plurality of cells to be recovered to a predetermined humidity state.
    Type: Application
    Filed: November 18, 2009
    Publication date: January 19, 2012
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Keigo Suematsu, Tomotaka Ishikawa, Yoshiaki Naganuma, I, Hiroyuki Katsuda