Patents by Inventor Nobuki Koiwa
Nobuki Koiwa 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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Patent number: 11799104Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply channel, a fuel gas circulation channel, a circulating pump that is driven by a pump motor having no rotation detecting sensor, and an ECU. When a method for operating the fuel cell system determines that the circulating pump is frozen in a low-temperature environment, the method performs a first step of performing a brake mode to limit the rotation of the pump motor while passing current to the pump motor, to thereby heat the pump motor. The method further performs a second step of, after rotating the pump motor, determining that the circulating pump has unfrozen if the rotational speed of the pump motor exceeds a given value.Type: GrantFiled: March 26, 2021Date of Patent: October 24, 2023Assignee: Honda Motor Co., Ltd.Inventors: Nobuki Koiwa, Masaoki Inamoto, Hideo Numata
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Patent number: 11563223Abstract: A fuel cell system includes a fuel cell stack, an anode system apparatus, a control unit, an anode outlet temperature sensor, and a purge valve. In a method of starting operation of the fuel cell system at low temperature, a control unit compares a predetermined freezing temperature threshold value with an anode outlet temperature detected by an anode outlet temperature sensor. Then, the control unit performs low temperature control to place the purge valve in the constantly open state in the case where the temperature is not higher than the freezing temperature threshold value, and performs normal control for switching opening/closing of the purge valve in the case where the temperature exceeds the freezing temperature threshold value.Type: GrantFiled: September 17, 2020Date of Patent: January 24, 2023Assignee: Honda Motor Co., Ltd.Inventors: Kazuhide Inoue, Jumpei Ogawa, Nobuki Koiwa
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Patent number: 11522206Abstract: A fuel cell system includes a fuel cell stack of a plurality of power generation cells and an impedance measuring device for measuring the impedance in the fuel cell stack. When stopping the operation of the fuel cell system, a method for stopping the operation of the fuel cell system operates the plurality of power generation cells to generate electric power, until the impedance value becomes equal to or greater than an objective impedance value. After the impedance value has become equal to or greater than the objective impedance value, the operation stopping method still continues the power generation of the multiple power generation cells for a given period of time.Type: GrantFiled: March 18, 2021Date of Patent: December 6, 2022Assignee: Honda Motor Co., Ltd.Inventors: Nobuki Koiwa, Shinya Watanabe, Yuji Matsumoto, Kazuhide Inoue
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Patent number: 11444294Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply channel, a fuel gas circulation channel, a circulating pump that is driven by a pump motor having no sensor, and an ECU for controlling the rotation of the pump motor. A method for operating the fuel cell system rotates the pump motor when starting, and stops the supply of electric power to the pump motor after the rotational speed of the pump motor has reached a given value, and determines, in an inertial period, whether or not the rotational speed of the pump motor has become equal to or lower than a predetermined value within a given time period.Type: GrantFiled: March 26, 2021Date of Patent: September 13, 2022Assignee: Honda Motor Co., Ltd.Inventors: Yusai Yoshimura, Hideo Numata, Nobuki Koiwa
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Patent number: 11398635Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply channel, a circulation passage, a purge valve, and a temperature sensor. A method of operating the fuel cell system performs a judging step of determining whether or not the temperature detected by the temperature sensor is at or below a given temperature. Then, if the temperature is at or below the given temperature, the method performs a purge valve scavenging process step of intermittently opening and closing the purge valve multiple times, while supplying the fuel gas through the fuel gas supply channel.Type: GrantFiled: March 30, 2021Date of Patent: July 26, 2022Assignee: Honda Motor Co., Ltd.Inventors: Nobuki Koiwa, Hideo Numata, Jumpei Ogawa, Yusai Yoshimura
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Publication number: 20210305596Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply channel, a fuel gas circulation channel, a circulating pump that is driven by a pump motor having no sensor, and an ECU for controlling the rotation of the pump motor. A method for operating the fuel cell system rotates the pump motor when starting, and stops the supply of electric power to the pump motor after the rotational speed of the pump motor has reached a given value, and determines, in an inertial period, whether or not the rotational speed of the pump motor has become equal to or lower than a predetermined value within a given time period.Type: ApplicationFiled: March 26, 2021Publication date: September 30, 2021Inventors: Yusai YOSHIMURA, Hideo NUMATA, Nobuki KOIWA
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Publication number: 20210305599Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply channel, a circulation passage, a purge valve, and a temperature sensor. A method of operating the fuel cell system performs a judging step of determining whether or not the temperature detected by the temperature sensor is at or below a given temperature. Then, if the temperature is at or below the given temperature, the method performs a purge valve scavenging process step of intermittently opening and closing the purge valve multiple times, while supplying the fuel gas through the fuel gas supply channel.Type: ApplicationFiled: March 30, 2021Publication date: September 30, 2021Inventors: Nobuki KOIWA, Hideo NUMATA, Jumpei OGAWA, Yusai YOSHIMURA
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Publication number: 20210305600Abstract: A fuel cell system includes a fuel cell stack, a fuel gas supply channel, a fuel gas circulation channel, a circulating pump that is driven by a pump motor having no rotation detecting sensor, and an ECU. When a method for operating the fuel cell system determines that the circulating pump is frozen in a low-temperature environment, the method performs a first step of performing a brake mode to limit the rotation of the pump motor while passing current to the pump motor, to thereby heat the pump motor. The method further performs a second step of, after rotating the pump motor, determining that the circulating pump has unfrozen if the rotational speed of the pump motor exceeds a given value.Type: ApplicationFiled: March 26, 2021Publication date: September 30, 2021Inventors: Nobuki KOIWA, Masaoki INAMOTO, Hideo NUMATA
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Publication number: 20210296667Abstract: A fuel cell system includes a fuel cell stack of a plurality of power generation cells and an impedance measuring device for measuring the impedance in the fuel cell stack. When stopping the operation of the fuel cell system, a method for stopping the operation of the fuel cell system operates the plurality of power generation cells to generate electric power, until the impedance value becomes equal to or greater than an objective impedance value. After the impedance value has become equal to or greater than the objective impedance value, the operation stopping method still continues the power generation of the multiple power generation cells for a given period of time.Type: ApplicationFiled: March 18, 2021Publication date: September 23, 2021Inventors: Nobuki KOIWA, Shinya WATANABE, Yuji MATSUMOTO, Kazuhide INOUE
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Publication number: 20210091394Abstract: A fuel cell system includes a fuel cell stack, an anode system apparatus, a control unit, an anode outlet temperature sensor, and a purge valve. In a method of starting operation of the fuel cell system at low temperature, a control unit compares a predetermined freezing temperature threshold value with an anode outlet temperature detected by an anode outlet temperature sensor. Then, the control unit performs low temperature control to place the purge valve in the constantly open state in the case where the temperature is not higher than the freezing temperature threshold value, and performs normal control for switching opening/closing of the purge valve in the case where the temperature exceeds the freezing temperature threshold value.Type: ApplicationFiled: September 17, 2020Publication date: March 25, 2021Inventors: Kazuhide INOUE, Jumpei OGAWA, Nobuki KOIWA
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Patent number: 10461349Abstract: A method for controlling a fuel cell system including a fuel cell, includes generating electric current via an electrochemical reaction between a fuel gas and an oxidant gas by the fuel cell including a solid polymer electrolyte membrane. An impedance of the fuel cell is detected. It is determined whether the impedance reaches a threshold impedance. The electric current generated by the fuel cell is increased when the impedance is determined to reach the threshold impedance.Type: GrantFiled: February 9, 2017Date of Patent: October 29, 2019Assignee: HONDA MOTOR CO., LTD.Inventors: Nobuki Koiwa, Osamu Ogami, Yuji Matsumoto, Kenji Taruya
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Patent number: 10249889Abstract: A fuel cell system comprises: a turbo type oxidizing agent pump, the rotary shaft of which is pivotally supported by an air bearing to take in and supply an oxidizing agent gas to a fuel cell by the rotary motion; an actual flow rate detection means for the oxidizing agent gas; a pressure adjustment means for the oxidizing agent gas; a rotary speed monitoring means for the oxidizing agent pump; and a control means which, when the rotary speed of the oxidizing agent pump is within the range of the minimum rotary speed that allows the rotary shaft to be pivotally supported by the air bearing, if the actual flow rate of the oxidizing agent gas is larger than a target flow rate, increases the pressure of the oxidizing agent gas via the pressure adjustment means.Type: GrantFiled: April 12, 2013Date of Patent: April 2, 2019Assignee: HONDA MOTOR CO., LTD.Inventors: Kenichiro Ueda, Kenji Taruya, Masakazu Hamachi, Nobuki Koiwa
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Patent number: 10230118Abstract: A method for controlling a fuel cell system including a fuel cell, includes measuring an impedance of the fuel cell that includes a solid polymer electrolyte membrane to generate electric power via an electrochemical reaction between a fuel gas and an oxidant gas. An output electric current output from the fuel cell is increased to a threshold electric current value when the impedance is equal to or higher than a threshold impedance value and a target electric current value is larger than the threshold electric current value. The output electric current is maintained at the threshold electric current value. The output electric current is increased from the threshold electric current value to the target electric current value.Type: GrantFiled: February 13, 2017Date of Patent: March 12, 2019Assignee: HONDA MOTOR CO., LTD.Inventors: Nobuki Koiwa, Osamu Ogami, Takashi Yamamoto, Yusai Yoshimura
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Patent number: 10205185Abstract: A method for controlling a fuel cell system includes supplying an oxidant gas, via an oxidant gas supply channel, to a cathode electrode of a fuel cell. The oxidant gas is moistened to be supplied to the cathode electrode with a humidifier. An opening degree of a bypass channel valve is decreased via a feedforward control to a first opening degree when an impedance has reached a lower limit value. The opening degree of the bypass channel valve is increased via the feedforward control to a second opening degree when the impedance has reached an upper limit value. The first opening degree is smaller than the second opening degree.Type: GrantFiled: February 28, 2017Date of Patent: February 12, 2019Assignee: HONDA MOTOR CO., LTD.Inventors: Nobuki Koiwa, Osamu Ogami, Shinya Watanabe, Takashi Yamamoto
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Patent number: 10050292Abstract: A method for controlling a fuel cell system including a fuel cell which includes an anode electrode and a cathode electrode sandwiching a solid polymer electrolyte membrane therebetween, includes driving a pump to supply an oxidant gas to the cathode electrode. The pump has a minimum supply amount of the oxidant gas. A fuel gas is supplied to the anode electrode to generate electric power via an electrochemical reaction between the fuel gas and the oxidant gas. It is determined whether a target amount of the oxidant gas to be supplied to the cathode electrode is lower than the minimum supply amount. An opening degree of a pressure adjusting valve is adjusted to adjust an amount of the oxidant gas supplied to the cathode electrode to be the target amount when the target amount is determined to be lower than the minimum supply amount.Type: GrantFiled: January 23, 2017Date of Patent: August 14, 2018Assignee: HONDA MOTOR CO., LTD.Inventors: Nobuki Koiwa, Osamu Ogami, Yusai Yoshimura, Akiji Ando
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Patent number: 9786935Abstract: A controller (control portion) of a fuel cell system is provided with a flow path switching control device that switches a thermostat valve (flow path switching valve) so that, after a fuel cell has stopped generating electric power, coolant is supplied to a radiator circulation path until the coolant temperature becomes a second temperature threshold value that is lower than a first temperature threshold value.Type: GrantFiled: May 31, 2013Date of Patent: October 10, 2017Assignee: HONDA MOTOR CO., LTD.Inventors: Koichiro Furusawa, Nobutaka Nakajima, Kaoru Yamazaki, Kenichiro Ueda, Nobuki Koiwa, Kenji Taruya, Masakazu Hamachi
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Patent number: 9761896Abstract: A method for stopping a fuel cell system includes supplying a fuel gas containing a fuel to an anode of a fuel cell which is to generate electric power. An oxidant gas containing an oxidant is supplied to a cathode of the fuel cell. A concentration of the oxidant gas in the cathode is reduced. An output voltage of the fuel cell is lowered while a slope of a change in the output voltage with respect to elapsed time is controlled such that an output current of the fuel cell has a predetermined relationship with a predetermined current reference value.Type: GrantFiled: June 25, 2015Date of Patent: September 12, 2017Assignee: HONDA MOTOR CO., LTD.Inventors: Kenji Taruya, Yuji Matsumoto, Nobuki Koiwa
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Publication number: 20170250415Abstract: A method for controlling a fuel cell system including a fuel cell, includes generating electric current via an electrochemical reaction between a fuel gas and an oxidant gas by the fuel cell including a solid polymer electrolyte membrane. An impedance of the fuel cell is detected. It is determined whether the impedance reaches a threshold impedance. The electric current generated by the fuel cell is increased when the impedance is determined to reach the threshold impedance.Type: ApplicationFiled: February 9, 2017Publication date: August 31, 2017Applicant: HONDA MOTOR CO., LTD.Inventors: Nobuki KOIWA, Osamu OGAMI, Yuji MATSUMOTO, Kenji TARUYA
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Publication number: 20170250425Abstract: A method for controlling a fuel cell system including a fuel cell, includes measuring an impedance of the fuel cell that includes a solid polymer electrolyte membrane to generate electric power via an electrochemical reaction between a fuel gas and an oxidant gas. An output electric current output from the fuel cell is increased to a threshold electric current value when the impedance is equal to or higher than a threshold impedance value and a target electric current value is larger than the threshold electric current value. The output electric current is maintained at the threshold electric current value. The output electric current is increased from the threshold electric current value to the target electric current value.Type: ApplicationFiled: February 13, 2017Publication date: August 31, 2017Applicant: HONDA MOTOR CO., LTD.Inventors: Nobuki KOIWA, Osamu OGAMI, Takashi YAMAMOTO, Yusai YOSHIMURA
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Publication number: 20170250423Abstract: A method for controlling a fuel cell system includes supplying an oxidant gas, via an oxidant gas supply channel, to a cathode electrode of a fuel cell. The oxidant gas is moistened to be supplied to the cathode electrode with a humidifier. An opening degree of a bypass channel valve is decreased via a feedforward control to a first opening degree when an impedance has reached a lower limit value. The opening degree of the bypass channel valve is increased via the feedforward control to a second opening degree when the impedance has reached an upper limit value. The first opening degree is smaller than the second opening degree.Type: ApplicationFiled: February 28, 2017Publication date: August 31, 2017Applicant: HONDA MOTOR CO., LTD.Inventors: Nobuki KOIWA, Osamu OGAMI, Shinya WATANABE, Takashi YAMAMOTO