Patents by Inventor Tomotaka Ishikawa
Tomotaka Ishikawa 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).
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Publication number: 20210376358Abstract: A fuel cell system includes a fuel cell a temperature acquisition unit that acquires a temperature of the fuel cell, a cell unit voltage sensor that detects a voltage of each of fuel cell units, and a controller that controls the fuel cell system. The controller restricts an output current of the fuel cell when the voltage of the individual fuel cell unit becomes equal to or lower than a predetermined value in a warm-up operation, execute the warm-up operation when the temperature of the fuel cell is equal to or lower than a predetermined temperature, after the fuel cell system receives a start-up request, and stop an operation of the fuel cell system when a stop condition including that the voltage of the fuel cell unit is continuously equal to or lower than a predetermined voltage value for a predetermined time is satisfied after start of the warm-up operation.Type: ApplicationFiled: March 31, 2021Publication date: December 2, 2021Inventors: Masashi TOIDA, Tomotaka ISHIKAWA, Yusuke NISHIDA
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Publication number: 20210376350Abstract: A fuel cell system includes a fuel cell, a first temperature sensor configured to acquire a first temperature that is a temperature of the fuel cell, a plurality of accessories that is used to operate the fuel cell, a second temperature sensor configured to acquire a second temperature that is a temperature of at least any one of the plurality of accessories, and a controller configured to perform control on the plurality of accessories to execute a warming-up operation of the fuel cell. The controller is configured to execute the warming-up operation when any of a first condition that the first temperature is lower than a predetermined first threshold temperature and a second condition that the first temperature is equal to or higher than the first threshold temperature and the second temperature is lower than a predetermined second threshold temperature is satisfied.Type: ApplicationFiled: April 7, 2021Publication date: December 2, 2021Inventors: Mahiro OZEKI, Tomotaka ISHIKAWA, Yusuke NISHIDA
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Publication number: 20210367245Abstract: A fuel cell system 1 is provided with a fuel cell 10 including a hydrogen passage 10h, a hydrogen supply path 31 connected to an inlet of a hydrogen passage, an injector 44 arranged in the hydrogen supply path, an anode off gas passage AP connected to an outlet of the hydrogen passage, and a drain control valve 46 provided in the anode off gas passage. Hydrogen replacement is performed in which the injector is opened so that a pressure inside the hydrogen passage becomes a required hydrogen pressure while the drain control valve is opened. The fuel cell system 1 is further provided with a pressure sensor 94a detecting the pressure inside the hydrogen passage. Hydrogen replacement is not performed when it is judged that the pressure inside the hydrogen passage is higher than the required hydrogen pressure.Type: ApplicationFiled: March 19, 2021Publication date: November 25, 2021Inventors: Yusuke NISHIDA, Tomotaka ISHIKAWA, Masashi TOIDA
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Publication number: 20210359316Abstract: A fuel cell system herein may include a battery configured to supply electric power to a fuel cell auxiliary device used for activating a fuel cell stack. When remaining electric energy in the battery is higher than an electric energy threshold upon activation of the fuel cell stack, a controller of the fuel cell system may start outputting current from the fuel cell stack after a fuel concentration in the fuel cell stack reaches a predetermined fuel concentration threshold, and when the remaining electric energy decreases below the electric energy threshold while the fuel concentration is being increased, the controller may start outputting current from the fuel cell stack regardless of the fuel concentration in the fuel cell stack. The current can be obtained from the fuel cell stack even when the remaining electric energy in the battery is low.Type: ApplicationFiled: April 2, 2021Publication date: November 18, 2021Inventors: Yusuke NISHIDA, Masashi TOIDA, Tomotaka ISHIKAWA
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Patent number: 11171349Abstract: A fuel cell vehicle comprises a fuel cell, a power storage device, a drive motor, a temperature sensor configured to measure a temperature of the fuel cell, a detector configured to detect an operation condition of the fuel cell, and a controller. At a start time of the fuel cell, in a case where the temperature of the fuel cell detected by the temperature sensor is below a freezing point, when an output condition of the fuel cell shown by the detected operation condition of the fuel cell continuously corresponds to a predetermined low output condition for a predetermined reference time period or longer, the controller sets a driving state of the fuel cell vehicle to a first driving state that stops power generation of the fuel cell, drives the drive motor by using only the power storage device as a power source and limits a motor output of the drive motor to be equal to or lower than a predetermined first upper limit output.Type: GrantFiled: June 12, 2019Date of Patent: November 9, 2021Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Tomohiro Ogawa, Tomotaka Ishikawa, Shinji Asou, Tomio Yamanaka, Junichi Matsuo, Ryosuke Oya
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Publication number: 20210328239Abstract: A fuel cell system includes a fuel cell stack and a control device that controls operation of the fuel cell system based on a measured voltage value measured by a voltage sensor. When the fuel cell system is started and a value measured by a temperature sensor is equal to or less than a temperature determined in advance, the control device raises the voltage of the fuel cell stack until a voltage condition determined in advance is met, by supplying a cathode with an oxidant gas before current sweep is started. The control device sets a voltage command value and a current command value such that an operation point of the fuel cell stack is on an equal power line of the fuel cell stack when the operation point is caused to transition in at least a part of a transition period.Type: ApplicationFiled: April 6, 2021Publication date: October 21, 2021Inventors: Ryouichi NAMBA, Masahiro ITO, Manabu Takahashi, Tomotaka ISHIKAWA
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Patent number: 11139494Abstract: A controller of a fuel cell system performs cathode gas supply control to raise an average cell voltage of a fuel cell stack by increasing supply of cathode gas to the fuel cell stack, when electric power required to be generated by the fuel cell stack is equal to zero, and the average cell voltage is lower than a predetermined target voltage. Under the cathode gas supply control, the controller sets the target voltage when a predetermined condition indicating that crossleak is likely to occur is satisfied, to a value higher than a reference target voltage as the target voltage in the case where the condition is not satisfied.Type: GrantFiled: October 8, 2018Date of Patent: October 5, 2021Assignee: Toyota Jidosha Kabushiki KaishaInventors: Ryoichi Namba, Tomotaka Ishikawa, Yoshikatsu Fujimura
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Publication number: 20210257635Abstract: A fuel cell system includes a fuel cell stack, an oxidizing gas supply system, a fuel gas supply system, a current control circuit configured to control an output current of the fuel cell stack, a control unit configured to control power generation of the fuel cell stack, and the output current of the current control circuit, the control unit controlling the current control circuit to adjust the output current thereby adjusting a heating value of the fuel cell stack; and a monitoring unit configured to monitor abnormal fuel gas generation, the abnormal fuel gas generation corresponding to a state where the fuel gas in excess of a predetermined allowable amount exists in the cathode. When the monitoring unit detects the abnormal fuel gas generation during execution of a warm-up operation to allow the fuel cell stack to generate heat with a predetermined target heating value, the control unit reduces the output current by reducing the target heating value.Type: ApplicationFiled: February 3, 2021Publication date: August 19, 2021Inventors: Ryouichi Namba, Masahiro Ito, Hiroyuki Tsunekawa, Tomotaka Ishikawa
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Patent number: 11011762Abstract: When a time period from a stop to a start of a fuel cell system exceeds a predetermined time period, a controller of the fuel cell system obtains a first electrical conductivity of a cooling medium that is placed from a radiator to before a connecting location of one end portion in a cooling medium circulation flow path and a second electrical conductivity of the cooling medium that is placed on a downstream side of an ion exchanger in a bypass flow path, and uses the obtained first electrical conductivity and second electrical conductivity and a predetermined target electrical conductivity of a supply cooling medium to control the operation of a flow dividing valve such that the electrical conductivity of the supply cooling medium becomes equal to or less than the target electrical conductivity and thereby regulate a flow rate ratio.Type: GrantFiled: June 18, 2019Date of Patent: May 18, 2021Assignee: Toyota Jidosha Kabushiki KaishaInventors: Keita Yamaue, Hiroyuki Imanishi, Tomotaka Ishikawa
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Patent number: 10957924Abstract: A fuel cell system comprises a fuel cell, a gas-liquid separator, a drain flow path through which moisture is discharged from the gas-liquid separator, a valve configured to control discharge of the moisture from the gas-liquid separator, and a controller configured to control fuel cell operation and opening and closing of the valve, and determine whether the valve is frozen. Upon receipt of a stop request of the fuel cell during the fuel cell operation, the controller repeatedly determines whether the valve is frozen. If the controller determines that the valve is frozen, it continues the fuel cell operation until it determines that the valve is not frozen. If the controller determines that the valve is not frozen, it executes stop processing of the fuel cell including opening valve processing.Type: GrantFiled: July 9, 2019Date of Patent: March 23, 2021Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Junichi Matsuo, Tomotaka Ishikawa, Tomohiro Ogawa, Tomio Yamanaka
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Publication number: 20210075045Abstract: A fuel cell system includes: a fuel cell generating electricity when being supplied with anode gas and cathode gas; a supply channel through which the anode gas to be supplied to the fuel cell flows; a discharge channel through which anode-off gas discharged from the fuel cell flows; a discharge valve provided on the discharge channel and opened to discharge the anode-off gas; and a control section controlling opening/closing of the discharge valve. The control section calculates a valve open time of the discharge valve corresponding to a target value of a discharge amount of the anode-off gas by using an aperture ratio of the discharge channel and the target value, and closes the discharge valve based on the valve open time, the aperture ratio of the discharge channel being calculated from a first discharge amount of the anode-off gas, which is discharged by opening of the discharge valve.Type: ApplicationFiled: July 2, 2020Publication date: March 11, 2021Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Yusuke NISHIDA, Tomotaka ISHIKAWA
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Patent number: 10930953Abstract: A control unit of a fuel cell system acquires a service operating point, repeats a process of calculating a distance between the service operating point and a surging region, while transferring an operating point of a turbo compressor from a first operating point to a second operating point outside the surging region, sets opening degrees of a pressure adjusting valve and a bypass valve such that the turbo compressor operates at a required operating point, when the distance exceeds a threshold, and corrects at least one of the opening degrees of the pressure adjusting valve and the bypass valve such that the at least one of the opening degrees becomes larger than an opening degree set such that the turbo compressor operates at the required operating point, when the distance is equal to or shorter than the threshold.Type: GrantFiled: January 15, 2019Date of Patent: February 23, 2021Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Atsuo Iio, Naoki Tomi, Yusuke Miyamoto, Masafumi Yamagata, Tomotaka Ishikawa
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Patent number: 10868316Abstract: 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: GrantFiled: January 3, 2019Date of Patent: December 15, 2020Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Tomohiro Ogawa, Tomotaka Ishikawa, Tomio Yamanaka, Ryoichi Nanba, Kenji Umayahara
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Patent number: 10845108Abstract: A refrigeration device includes a refrigerant circuit sequentially connecting a compressor, a condenser, a reservoir, and a subcooling coil via refrigerant pipes in series, an injection circuit configured to inject part of refrigerant flowing from the condenser to an intermediate pressure part of the compressor, and an injection expansion valve configured to reduce a pressure of refrigerant branched on a downstream side of the subcooling coil. The refrigeration device includes a temperature measurement unit, a pressure measurement unit, and a controller configured to identify a type of refrigerant on the basis of a measured value of the temperature measurement unit and a measured value of the pressure measurement unit, and control at least one of an operating frequency of the compressor, a rotation frequency of a condenser fan, and an opening degree of the injection expansion valve.Type: GrantFiled: February 8, 2016Date of Patent: November 24, 2020Assignee: Mitsubishi Electric CorporationInventors: Ryo Tsukiyama, Yusuke Arii, Tomotaka Ishikawa
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Patent number: 10756364Abstract: There is provided a fuel cell system comprising a fuel cell including an electrolyte membrane, an anode and a cathode; and a controller configured to control a fuel gas supply part and an oxidizing gas supply part to supply amounts of a fuel gas and an oxidizing gas corresponding to a required power, to the fuel cell. During an intermittent operation that has the required power equal to or lower than a predetermined value and stops power generation in the fuel cell, the controller estimates a crossover amount that is an amount of the fuel gas moved from the anode to the cathode through the electrolyte membrane. The controller also calculates a supply amount of the oxidizing gas that is an amount of the oxidizing gas to be supplied to the fuel cell, based on the estimated crossover amount and controls the oxidizing gas supply part to supply the calculated supply amount of the oxidizing gas to the fuel cell.Type: GrantFiled: May 9, 2018Date of Patent: August 25, 2020Assignee: Toyota Jidosha Kabushiki KaishaInventors: Yusuke Miyamoto, Tomotaka Ishikawa, Atsuo Iio
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Patent number: 10714772Abstract: A fuel cell system comprises a fuel cell, a cooling system, a rotating speed acquisition part acquiring a rotating speed of the refrigerant pump, a power consumption acquisition part acquiring a power consumption of the refrigerant pump, and a controller configured to receive a rotating speed acquired by the rotating speed acquisition part and control the refrigerant pump. The controller has stored therein a predetermined correspondence between rotating speeds of the refrigerant pump and power consumption threshold values.Type: GrantFiled: May 30, 2017Date of Patent: July 14, 2020Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Tomoyuki Nishida, Tomotaka Ishikawa, Keitaro Yamamori
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Publication number: 20200200457Abstract: A refrigeration cycle apparatus is a refrigeration cycle apparatus having a refrigerant circuit having a compressor, a condenser, a supercooler, an expansion device, and an evaporator connected by a refrigerant pipe, and configured to circulate refrigerant containing refrigerant having a temperature gradient, wherein the supercooler sets a degree of supercooling of the refrigerant, which is a temperature difference between a temperature from the condenser to a refrigerant flow inlet of the supercooler and a temperature in a refrigerant flow outlet on a downstream side of the supercooler, to be larger than the temperature gradient generated at a time of refrigerant shortage of the refrigerant between the refrigerant flow inlet and the refrigerant flow outlet of the supercooler, the refrigeration cycle apparatus including a refrigerant amount determination unit configured to compare a determination threshold value set to a value larger than the temperature gradient of the refrigerant with the degree of supercooType: ApplicationFiled: September 14, 2017Publication date: June 25, 2020Inventors: Hiroshi SATA, Tomotaka ISHIKAWA
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Patent number: 10693160Abstract: A fuel cell system includes a fuel cell stack, a compressor that supplies cathode gas to the fuel cell stack, and a controller that controls constituent components of the fuel cell system including the compressor. The controller controls the compressor, such that a supply period in which the compressor supplies the cathode gas and a stop period in which supply of the cathode gas is stopped appear alternately, when the fuel cell stack is not required to generate electric power, and the supply period is longer than the stop period, and such that the flow rate of the cathode gas supplied by the compressor in the supply period is smaller than the flow rate in the case where the fuel cell stack is required to generate electric power.Type: GrantFiled: September 26, 2018Date of Patent: June 23, 2020Assignee: Toyota Jidosha Kabushiki KaishaInventors: Ryoichi Namba, Tomotaka Ishikawa
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Publication number: 20200144644Abstract: A fuel cell system comprises a fuel cell, coolant, a gas-liquid separator, a gas-liquid discharge valve, and a controller. The controller includes an exhaust speed acquisition unit configured to obtain an exhaust speed A of anode off gas discharged from the gas-liquid discharge valve, a threshold speed setting unit configured to set an exhaust speed B, serving as a threshold speed, based on an exhaust speed A1 obtained in a warmed-up state in which temperature of the coolant is equal to or higher than predetermined temperature, and a gas-liquid discharge valve normality determination unit configured to compare an exhaust speed A2, obtained at the time after the exhaust speed B is set by the threshold speed setting unit and when environmental temperature is below zero, with the set threshold speed so as to perform a normal valve opening determination to determine whether the gas-liquid discharge valve opens normally.Type: ApplicationFiled: September 27, 2019Publication date: May 7, 2020Inventors: Tomio YAMANAKA, Tomotaka ISHIKAWA
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Patent number: 10601059Abstract: A fuel cell system comprises: a fuel gas supplier: an air supplier; an air flow rate acquirer that obtains a flow rate of the air that is supplied to a fuel cell; a voltage acquirer that obtains an output voltage of the fuel cell; and a controller. At the time of starting the fuel cell system, the controller controls the fuel gas supplier to supply a fuel gas to the fuel cell for a first time period. After elapse of the first time period, the controller controls the air supplier to start supply of the air. The controller calculates an integrated value of the flow rate for a second time period after the supply of the air is started. When the integrated value becomes greater than a predetermined amount and the output voltage is less than a predetermined voltage, the controller determines that the fuel cell system has an abnormality.Type: GrantFiled: July 18, 2017Date of Patent: March 24, 2020Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Tomio Yamanaka, Tomotaka Ishikawa