Patents by Inventor Keiichiro Aoki
Keiichiro Aoki 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: 20240141847Abstract: When the element temperature of the air-fuel ratio sensor becomes equal to or higher than the activation temperature, the electronic control unit starts the detection of the air-fuel ratio based on the sensor output of the air-fuel ratio sensor and the air-fuel ratio feedback control based on the detection result. The electronic control unit calculates the air-fuel ratio detection value by setting the gain of the air-fuel ratio detection value with respect to the sensor output when the sensor output is a value indicating the air-fuel ratio richer than the stoichiometric air-fuel ratio to a value smaller than that after the elapse of the synchronization period from the start of the air-fuel ratio until the element temperature becomes equal to or higher than the predetermined desorption convergence temperature.Type: ApplicationFiled: August 7, 2023Publication date: May 2, 2024Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Keiichiro AOKI, Masato IKEMOTO
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Patent number: 11948740Abstract: To provide an electrode for an electricity storage device, which electrode employs a porous conductor having conductive nanostructures formed on its surface and makes it possible to provide a less expensive electricity storage device having a high discharge capacity and high charge/discharge cycle resistance. A porous conductor which is used as an electrode for an electricity storage device has a plurality of conductive nanostructures on a surface of the porous conductor.Type: GrantFiled: September 19, 2018Date of Patent: April 2, 2024Assignees: National University Corporation Chiba University, TOMOEGAWA CORPORATIONInventors: Katsuyoshi Hoshino, Yousuke Sugawara, Rio Yamada, Aoi Magori, Nobuyuki Aoki, Keiichiro Haji, Daisuke Muramatsu
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Patent number: 11920532Abstract: An exhaust gas control apparatus for an internal combustion engine includes: a catalyst which is capable of storing oxygen; a downstream air-fuel ratio sensor that detects the air-fuel ratio of outgoing exhaust gas flowing out of the catalyst; an air-fuel ratio control unit that controls the air-fuel ratio of incoming exhaust gas flowing into the catalyst; and a catalyst state estimation unit that estimates the activity of the catalyst. The air-fuel ratio control unit controls the air-fuel ratio of the incoming exhaust gas so that the air-fuel ratio of the outgoing exhaust gas detected by the downstream air-fuel ratio sensor is maintained at a target air-fuel ratio. The air-fuel ratio control unit sets the target air-fuel ratio to a richer value when the activity of the catalyst is equal to or higher than a predetermined value than when the activity of the catalyst is lower than the predetermined value.Type: GrantFiled: May 11, 2023Date of Patent: March 5, 2024Assignee: Toyota Jidosha Kabushiki KaishaInventor: Keiichiro Aoki
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Patent number: 11898511Abstract: A control device for an internal combustion engine includes an electronic control unit that controls the air-fuel ratio of incoming exhaust gas flowing into a catalyst. The electronic control unit performs oxygen amount variation control in which a target air-fuel ratio for the incoming exhaust gas is switched between a rich set air-fuel ratio and a lean set air-fuel ratio. The electronic control unit switches the target air-fuel ratio to the rich set air-fuel ratio when an air-fuel ratio detected by an air-fuel ratio sensor is equal to or higher than a predetermined oxygen saturation determination air-fuel ratio. The oxygen saturation determination air-fuel ratio is leaner than an oxygen depletion determination air-fuel ratio and richer than the stoichiometric air-fuel ratio.Type: GrantFiled: May 11, 2023Date of Patent: February 13, 2024Assignee: Toyota Jidosha Kabushiki KaishaInventor: Keiichiro Aoki
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Publication number: 20240018918Abstract: An exhaust gas control apparatus for an internal combustion engine includes: a catalyst which is capable of storing oxygen; a downstream air-fuel ratio sensor that detects the air-fuel ratio of outgoing exhaust gas flowing out of the catalyst; an air-fuel ratio control unit that controls the air-fuel ratio of incoming exhaust gas flowing into the catalyst; and a catalyst state estimation unit that estimates the activity of the catalyst. The air-fuel ratio control unit controls the air-fuel ratio of the incoming exhaust gas so that the air-fuel ratio of the outgoing exhaust gas detected by the downstream air-fuel ratio sensor is maintained at a target air-fuel ratio. The air-fuel ratio control unit sets the target air-fuel ratio to a richer value when the activity of the catalyst is equal to or higher than a predetermined value than when the activity of the catalyst is lower than the predetermined value.Type: ApplicationFiled: May 11, 2023Publication date: January 18, 2024Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Keiichiro AOKI
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Publication number: 20240018919Abstract: A control device for an internal combustion engine includes an electronic control unit that controls the air-fuel ratio of incoming exhaust gas flowing into a catalyst. The electronic control unit performs oxygen amount variation control in which a target air-fuel ratio for the incoming exhaust gas is switched between a rich set air-fuel ratio and a lean set air-fuel ratio. The electronic control unit switches the target air-fuel ratio to the rich set air-fuel ratio when an air-fuel ratio detected by an air-fuel ratio sensor is equal to or higher than a predetermined oxygen saturation determination air-fuel ratio. The oxygen saturation determination air-fuel ratio is leaner than an oxygen depletion determination air-fuel ratio and richer than the stoichiometric air-fuel ratio.Type: ApplicationFiled: May 11, 2023Publication date: January 18, 2024Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Keiichiro AOKI
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Patent number: 11828243Abstract: An exhaust gas control apparatus for an internal combustion engine includes: a catalyst disposed in an exhaust passage of the engine and configured to be able to occlude oxygen; an air-fuel ratio sensor that detects an air-fuel ratio of an out-flow exhaust gas; and an air-fuel ratio control device that controls an air-fuel ratio of an in-flow exhaust gas to a target air-fuel ratio. The device executes air-fuel ratio reduction control in which the target air-fuel ratio is set to a rich setting air-fuel ratio, and corrects a parameter related to the air-fuel ratio reduction control such that an amount of a reducing gas supplied to the catalyst is decreased when a minimum air-fuel ratio obtained when the detected air-fuel ratio is varied to a rich side is richer than the rich setting air-fuel ratio or an average value of detected air-fuel ratios of the in-flow exhaust gas.Type: GrantFiled: February 15, 2023Date of Patent: November 28, 2023Assignee: Toyota Jidosha Kabushiki KaishaInventor: Keiichiro Aoki
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Publication number: 20230340918Abstract: An exhaust gas control apparatus for an internal combustion engine includes: a catalyst disposed in an exhaust passage of the engine and configured to be able to occlude oxygen; an air-fuel ratio sensor that detects an air-fuel ratio of an out-flow exhaust gas; and an air-fuel ratio control device that controls an air-fuel ratio of an in-flow exhaust gas to a target air-fuel ratio. The device executes air-fuel ratio reduction control in which the target air-fuel ratio is set to a rich setting air-fuel ratio, and corrects a parameter related to the air-fuel ratio reduction control such that an amount of a reducing gas supplied to the catalyst is decreased when a minimum air-fuel ratio obtained when the detected air-fuel ratio is varied to a rich side is richer than the rich setting air-fuel ratio or an average value of detected air-fuel ratios of the in-flow exhaust gas.Type: ApplicationFiled: February 15, 2023Publication date: October 26, 2023Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Keiichiro AOKI
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Publication number: 20230340920Abstract: An exhaust gas control apparatus for an internal combustion engine includes: a catalyst disposed in an exhaust passage of the internal combustion engine and capable of occluding oxygen; an air-fuel ratio sensor that detects the air-fuel ratio of an out-flow exhaust gas that flows out of the catalyst; and an air-fuel ratio control device that controls the air-fuel ratio of an in-flow exhaust gas that flows into the catalyst. The air-fuel ratio control device starts slightly rich control in which the air-fuel ratio of the in-flow exhaust gas is controlled such that the air-fuel ratio of the out-flow exhaust gas is maintained at a slightly rich setting air-fuel ratio that is richer than a stoichiometric air-fuel ratio, when the air-fuel ratio of the out-flow exhaust gas is reduced to be equal to or less than a rich-side switching air-fuel ratio that is richer than the stoichiometric air-fuel ratio.Type: ApplicationFiled: February 16, 2023Publication date: October 26, 2023Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Keiichiro AOKI
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Patent number: 11401877Abstract: A control device selectively executes first and second energization control for controlling an energization amount to the heater. The first energization control is executed to keep temperature of a sensor element within an active temperature region. The first energization control is PWM control in which the energization amount is controlled with closed loop control such that an impedance of the sensor element matches a target value. The second energization control is PWM control in which the energization amount is controlled with open loop control so as to keep the temperature of the sensor element within a preset temperature region that is lower than the active temperature region. The control device executes the second energization control during an internal combustion engine is stopped while executing the first energization control during the internal combustion engine is not stopped.Type: GrantFiled: June 23, 2021Date of Patent: August 2, 2022Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Keiichiro Aoki
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Patent number: 11319889Abstract: The abnormality diagnosis system 1 of a downstream side air-fuel ratio detection device 41, 42, comprises an air-fuel ratio control part 71 controlling an air-fuel ratio of an air-fuel mixture, an abnormality judgment part 72 judging abnormality of the downstream side air-fuel ratio detection device based on a characteristic of change of output of the downstream side air-fuel ratio detection device when the air-fuel ratio control part makes the air-fuel ratio of the air-fuel mixture change, and an oxygen change calculation part 73 calculating an amount of change of an oxygen storage amount of the catalyst when the air-fuel ratio control part makes the air-fuel ratio of the air-fuel mixture change. The abnormality judgment part does not judge abnormality of the downstream side air-fuel ratio detection device when the amount of change of the oxygen storage amount is less than a lower limit threshold value.Type: GrantFiled: December 29, 2020Date of Patent: May 3, 2022Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Yoshiyuki Kitazume, Kazuhiro Wakao, Keiichiro Aoki, Yasutaka Kamiya
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Patent number: 11319890Abstract: An abnormality detection device for an air-fuel ratio detection device arranged downstream of a filter is equipped with an abnormality detection unit that detects an abnormality in the air-fuel ratio detection device based on output change characteristics of the air-fuel ratio detection device during fuel cutoff control for stopping the supply of fuel to a combustion chamber of an internal combustion engine, and a combustion determination unit that determines whether or not a combustion amount of particulate matter in a filter during fuel cutoff control is larger than a predetermined amount. The abnormality detection unit prohibits detection of an abnormality in the air-fuel ratio detection device when the combustion determination unit determines that the combustion amount is larger than the predetermined amount.Type: GrantFiled: January 13, 2021Date of Patent: May 3, 2022Assignee: Toyota Jidosha Kabushiki KaishaInventors: Kazuhiro Wakao, Yoshiyuki Kitazume, Keiichiro Aoki, Yasutaka Kamiya
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Publication number: 20220025807Abstract: A SOx concentration acquiring apparatus of an internal combustion engine of the invention acquires sensor currents as SOx concentration currents after a sensor voltage reaches an oxygen decreasing voltage in a reoxidation voltage decreasing control, acquires the sensor current as a base current when the sensor voltage is equal to or lower than the oxygen decreasing voltage in the reoxidation voltage decreasing control, acquires an integration value of differences between the base current and each of the SOx concentration currents, and acquires a SOx concentration of an exhaust gas discharged from an internal combustion engine on the basis of the integration value.Type: ApplicationFiled: October 7, 2021Publication date: January 27, 2022Applicant: Toyota Jidosha Kabushiki KaishaInventors: Kazuhisa MATSUDA, Kazuhiro WAKAO, Keiichiro AOKI
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Publication number: 20210404400Abstract: A control device selectively executes first and second energization control for controlling an energization amount to the heater. The first energization control is executed to keep temperature of a sensor element within an active temperature region. The first energization control is PWM control in which the energization amount is controlled with closed loop control such that an impedance of the sensor element matches a target value. The second energization control is PWM control in which the energization amount is controlled with open loop control so as to keep the temperature of the sensor element within a preset temperature region that is lower than the active temperature region. The control device executes the second energization control during an internal combustion engine is stopped while executing the first energization control during the internal combustion engine is not stopped.Type: ApplicationFiled: June 23, 2021Publication date: December 30, 2021Inventor: Keiichiro AOKI
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Patent number: 11199148Abstract: A control device for an exhaust sensor is configured to control the exhaust sensor disposed in an exhaust passage of an internal combustion engine. The control device for an exhaust sensor includes: a sensor element; a heater configured to heat the sensor element; a current detection circuit configured to detect an output current of the exhaust sensor, and an electronic control device configured to control electric power that is supplied to the heater by PWM control.Type: GrantFiled: January 26, 2021Date of Patent: December 14, 2021Assignee: Toyota Jidosha Kabushiki KaishaInventors: Kazuhiro Wakao, Keiichiro Aoki, Yasutaka Kamiya
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Publication number: 20210285394Abstract: A control device for an exhaust sensor is configured to control the exhaust sensor disposed in an exhaust passage of an internal combustion engine. The control device for an exhaust sensor includes: a sensor element; a heater configured to heat the sensor element; a current detection circuit configured to detect an output current of the exhaust sensor, and an electronic control device configured to control electric power that is supplied to the heater by PWM control.Type: ApplicationFiled: January 26, 2021Publication date: September 16, 2021Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kazuhiro WAKAO, Keiichiro AOKI, Yasutaka KAMIYA
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Patent number: 11092102Abstract: A sensor system for an engine for which an automatic stop-restart control is performed, the sensor system including: an exhaust gas sensor including a heater that heats a sensor element; and a control unit configured to: while the engine is stopped by the automatic stop-restart control, execute a preheat control of adjusting a temperature of the sensor element to a preheat temperature lower than an activation temperature; when an automatic start condition is satisfied, stop the preheat control and increase the temperature of the sensor element to the activation temperature; when an automatic stop condition is satisfied and a delay condition has not been satisfied, set the preheat temperature to a first temperature; and when the automatic stop condition is satisfied and the delay condition has been satisfied, set the preheat temperature to a second temperature higher than the first temperature.Type: GrantFiled: February 1, 2019Date of Patent: August 17, 2021Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Keiichiro Aoki, Mie Kato, Kazuki Takahashi
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Patent number: 11092100Abstract: A control system of an internal combustion engine comprises an air-fuel ratio sensor 40, 41 detecting an air-fuel ratio of exhaust gas, a current detecting device 61 detecting an output current of the air-fuel ratio sensor, a voltage applying device 60 applying voltage to the air-fuel ratio sensor, and a voltage control part 81 configured to control voltage applied to the air-fuel ratio sensor through the voltage applying device. The voltage control part is configured to set the applied voltage to a reference voltage determined so that the output current becomes zero when an air-fuel ratio of inflowing exhaust gas flowing into the air-fuel ratio sensor is a stoichiometric air-fuel ratio, and correct the reference voltage so that the output current detected by the current detecting device becomes zero when it is judged that the air-fuel ratio of the inflowing exhaust gas is the stoichiometric air-fuel ratio.Type: GrantFiled: January 3, 2020Date of Patent: August 17, 2021Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Keiichiro Aoki
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Publication number: 20210239062Abstract: An abnormality detection device for an air-fuel ratio detection device arranged downstream of a filter is equipped with an abnormality detection unit that detects an abnormality in the air-fuel ratio detection device based on output change characteristics of the air-fuel ratio detection device during fuel cutoff control for stopping the supply of fuel to a combustion chamber of an internal combustion engine, and a combustion determination unit that determines whether or not a combustion amount of particulate matter in a filter during fuel cutoff control is larger than a predetermined amount. The abnormality detection unit prohibits detection of an abnormality in the air-fuel ratio detection device when the combustion determination unit determines that the combustion amount is larger than the predetermined amount.Type: ApplicationFiled: January 13, 2021Publication date: August 5, 2021Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kazuhiro WAKAO, Yoshiyuki KITAZUME, Keiichiro AOKI, Yasutaka KAMIYA
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Patent number: 11078858Abstract: A control apparatus for an internal combustion engine includes an exhaust gas sensor that has a sensor element and a heater for electrically heating the sensor element, a sensor circuit that detects the electric current generated by the exhaust gas sensor, a controller configured to: carry out starting processing to start the internal combustion engine, learn a value of the output of the sensor circuit when the starting processing is carried out by the controller, and control a temperature of the sensor element by using the heater, and controls the temperature of the sensor element to less than the predetermined temperature until the learning of the output value of the sensor circuit by the controller is completed after the starting processing is carried out by the controller.Type: GrantFiled: February 12, 2019Date of Patent: August 3, 2021Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Keiichiro Aoki, Kazuki Takahashi