Patents by Inventor Ryozo Kayama

Ryozo Kayama 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: 11035283
    Abstract: A microcomputer includes a voltage application unit that selectively applies a normal voltage and a removal voltage higher than the normal voltage to a first cell of the exhaust gas sensor. The first cell is configured to remove, based on the removal voltage, oxygen in an exhaust gas from an internal combustion engine. The microcomputer includes an element temperature measurement unit that measures an element temperature parameter indicative of a temperature of the first cell. The microcomputer includes a termination determination unit that determines, based on the element temperature parameter, a termination time of terminating the application of the removal voltage to the first cell by the voltage application unit.
    Type: Grant
    Filed: March 27, 2020
    Date of Patent: June 15, 2021
    Assignee: DENSO CORPORATION
    Inventors: Yuki Murayama, Ryozo Kayama, Yusuke Todo, Manabu Yoshidome
  • Publication number: 20200264127
    Abstract: A first cell includes a first electrode in a measurement gas chamber and a second electrode in a reference gas chamber. A second cell includes a third electrode in the measurement gas chamber and a fourth electrode in the reference gas chamber to cause a current therebetween that corresponds to a concentration of a specific gas component in detected gas in the measurement chamber. A controller selectively implements a normal control and a reduction control. The normal control is to apply a lower voltage to the first electrode and the second electrode to remove oxygen from the detected gas. The reduction control is to apply a higher voltage to the first electrode and the second electrode to reduce the third electrode that is oxidized. The controller prohibits implementation of the reduction control on determination that implementation of the reduction control.
    Type: Application
    Filed: February 5, 2020
    Publication date: August 20, 2020
    Inventors: Shoki SHIMIZU, Ryozo KAYAMA, Yuki MURAYAMA
  • Publication number: 20200224600
    Abstract: It is to determine whether a temperature rise condition of a first cell or a second cell is satisfied based on whether a first parameter has exceeded a predetermined first threshold or a second parameter has exceeded a predetermined second threshold. After satisfaction of the temperature rise condition, it is to determine that an exhaust gas sensor is in an active state upon determination that a corresponding time condition is satisfied.
    Type: Application
    Filed: March 27, 2020
    Publication date: July 16, 2020
    Inventors: Yuki MURAYAMA, Ryozo KAYAMA, Yusuke TODO, Manabu YOSHIDOME
  • Publication number: 20200224575
    Abstract: A microcomputer includes a voltage application unit that selectively applies a normal voltage and a removal voltage higher than the normal voltage to a first cell of the exhaust gas sensor. The first cell is configured to remove, based on the removal voltage, oxygen in an exhaust gas from an internal combustion engine. The microcomputer includes an element temperature measurement unit that measures an element temperature parameter indicative of a temperature of the first cell. The microcomputer includes a termination determination unit that determines, based on the element temperature parameter, a termination time of terminating the application of the removal voltage to the first cell by the voltage application unit.
    Type: Application
    Filed: March 27, 2020
    Publication date: July 16, 2020
    Inventors: Yuki MURAYAMA, Ryozo KAYAMA, Yusuke TODO, Manabu YOSHIDOME
  • Patent number: 10690028
    Abstract: An abnormality detection device for an engine system detects an abnormality in a fuel vapor pipe connected to an intake pipe of an engine at a portion upstream of a supercharger in a flow direction of intake air. The abnormality detection device includes an intake air temperature sensor and an abnormality detection portion. The intake air temperature sensor is fitted to the intake pipe on an upstream side of the supercharger in the flow direction of intake air and detects a temperature of intake air mixed with fuel vapor introduced into the intake pipe from the fuel vapor pipe. The abnormality detection portion detects an abnormality in the fuel vapor pipe according to a detection value of intake air detected by the intake air temperature sensor.
    Type: Grant
    Filed: September 26, 2016
    Date of Patent: June 23, 2020
    Assignee: DENSO CORPORATION
    Inventors: Ryozo Kayama, Masanori Kurosawa
  • Patent number: 10634643
    Abstract: A NOx sensor includes a pump cell, a monitor cell, and a sensor cell, and the pump cell discharges an oxygen in an exhaust gas introduced into a chamber. The sensor cell outputs a detected signal depending on a concentration of a NOx according to a gas after the oxygen is discharged. A microcomputer of a sensor control circuit temporarily changes an amount of the oxygen discharged by the pump cell, and then calculates output change amounts ?Ip, ?Is, and ?Im of the cells. The microcomputer performs a correction of the concentration of the NOx detected by the sensor cell and a deterioration diagnosis of the sensor cell, based on the output change amounts ?Ip, ?Is, and ?Im of the cells. When the sensor cell current Is is smaller than the monitor cell current Im, the microcomputer determines that the NOx sensor has an abnormality.
    Type: Grant
    Filed: December 11, 2017
    Date of Patent: April 28, 2020
    Assignee: DENSO CORPORATION
    Inventors: Ryozo Kayama, Yukihiro Yamashita, Yoshihiro Sakashita
  • Publication number: 20200088673
    Abstract: Each of SCUs to includes: a voltage switching unit that performs a first voltage switching to increase an oxygen concentration in a gas chamber and a second voltage switching to decrease the oxygen concentration in the gas chamber after the execution of the first voltage switching; an output change calculation unit that calculates an output change parameter indicating a change in output of the sensor cell according to the voltage switching; a concentration difference calculation unit that calculates a concentration difference parameter indicating a concentration difference in the oxygen concentration or in the concentration of the specific gas in the detection target gas between before the first voltage switching and after the second voltage switching; and a deterioration determination unit that determines a deterioration state of the sensor cell based on the output change parameter and the concentration difference parameter.
    Type: Application
    Filed: November 22, 2019
    Publication date: March 19, 2020
    Inventors: Tadakatsu KOYABU, Yuki MURAYAMA, Ryozo KAYAMA, Akari HASEGAWA, Yusuke KAWAMOTO
  • Patent number: 10564120
    Abstract: A gas concentration detection device includes a pump cell, a sensor cell, a monitor cell, a sensor current detection unit detecting a current outputted by the sensor cell, a monitor current detection unit detecting a current outputted by the monitor cell, a voltage adjustment unit adjusting a pump cell voltage applied to the pump cell, and a sensitivity determination unit determining a gas sensitivity of at least one of the sensor cell or the monitor cell. The voltage adjustment unit changes the pump cell voltage from a target voltage into a detection voltage where the concentration of the residual oxygen supplied to the sensor cell and the monitor cell is increased. The sensitivity determination unit determines the gas sensitivity based on a detection current detected by at least one of the sensor current detection unit or the monitor current detection unit in accordance with the concentration of the residual oxygen.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: February 18, 2020
    Assignee: DENSO CORPORATION
    Inventors: Ryozo Kayama, Yukihiro Yamashita
  • Publication number: 20190219537
    Abstract: In a control device for an exhaust gas sensor, a deterioration determination section determines whether the magnitude of a signal outputted from a second cell has exceeded a threshold to thereby determine whether a first cell has deteriorated. A threshold setting section variably sets the threshold depending on a concentration of the oxygen in the exhaust gas.
    Type: Application
    Filed: January 17, 2019
    Publication date: July 18, 2019
    Inventors: Shoki SHIMIZU, Ryozo KAYAMA, Tadakatsu KOYABU, Yuki MURAYAMA
  • Patent number: 10234420
    Abstract: A NOx sensor includes a pump cell, a monitor cell, and a sensor cell, and the pump cell discharges an oxygen in an exhaust gas introduced into a chamber. The sensor cell outputs a detected signal depending on a concentration of a NOx according to a gas after the oxygen is discharged. A microcomputer of a sensor control circuit temporarily changes an amount of the oxygen discharged by the pump cell, and then calculates output change amounts ?Ip, ?Is, and ?Im of the cells. The microcomputer performs a correction of the concentration of the NOx detected by the sensor cell and a deterioration diagnosis of the sensor cell, based on the output change amounts ?Ip, ?Is, and ?Im of the cells. When the sensor cell current Is is smaller than the monitor cell current Im, the microcomputer determines that the NOx sensor has an abnormality.
    Type: Grant
    Filed: September 11, 2014
    Date of Patent: March 19, 2019
    Assignee: DENSO CORPORATION
    Inventors: Ryozo Kayama, Yukihiro Yamashita, Yoshihiro Sakashita
  • Patent number: 10174698
    Abstract: A heater control device for an exhaust gas sensor disposed in an exhaust gas passage of an internal combustion engine and including a sensor element having a plurality of cells, and a heater heating the sensor element includes: a heater power control unit configured to execute a temp rising control, in which an impedance of one cell to be measured, of the plurality of cells, is detected and a temperature of the sensor element is raised until the impedance of the one cell reaches a target impedance by setting a power control value of the heater as a heating power control value. The heater power control unit continues the temp rising control until an extension period elapses that is needed for the other cell other than the one cell to reach an activation temperature after the impedance of the one cell reaches the target impedance.
    Type: Grant
    Filed: April 8, 2015
    Date of Patent: January 8, 2019
    Assignee: DENSO CORPORATION
    Inventors: Yoshihiro Sakashita, Yukihiro Yamashita, Ryozo Kayama
  • Publication number: 20180340909
    Abstract: In a gas sensor, a pump cell adjusts a concentration of oxygen in a gas chamber based of a pump cell supply voltage. A sensor cell detects a concentration of a specific gas in a detection target gas after the pump cell has adjusted the concentration of oxygen. In a sensor control unit, a voltage switching part adjusts the pump cell supply voltage to be supplied to the pump cell. A pump cell output control part adjusts a variation range of a pump cell output current of the pump cell before and after a voltage switching process of the pump cell supply voltage to be within a predetermined variation range. A deteriorated state detection part detects a deteriorated state ratio of the sensor cell based on variation of an output current of the sensor cell due to the voltage switching process performed by the voltage switching part.
    Type: Application
    Filed: May 24, 2018
    Publication date: November 29, 2018
    Inventors: Tadakatsu KOYABU, Tomoo KAWASE, Yuki MURAYAMA, Ryozo KAYAMA, Akari HASEGAWA, Shoki SHIMIZU
  • Publication number: 20180306074
    Abstract: An abnormality detection device for an engine system detects an abnormality in a fuel vapor pipe connected to an intake pipe of an engine at a portion upstream of a supercharger in a flow direction of intake air. The abnormality detection device includes an intake air temperature sensor and an abnormality detection portion. The intake air temperature sensor is fitted to the intake pipe on an upstream side of the supercharger in the flow direction of intake air and detects a temperature of intake air mixed with fuel vapor introduced into the intake pipe from the fuel vapor pipe. The abnormality detection portion detects an abnormality in the fuel vapor pipe according to a detection value of intake air detected by the intake air temperature sensor.
    Type: Application
    Filed: September 26, 2016
    Publication date: October 25, 2018
    Inventors: Ryozo KAYAMA, Masanori KUROSAWA
  • Publication number: 20180106755
    Abstract: A NOx sensor includes a pump cell, a monitor cell, and a sensor cell, and the pump cell discharges an oxygen in an exhaust gas introduced into a chamber. The sensor cell outputs a detected signal depending on a concentration of a NOx according to a gas after the oxygen is discharged. A microcomputer of a sensor control circuit temporarily changes an amount of the oxygen discharged by the pump cell, and then calculates output change amounts ?Ip, ?Is, and ?Im of the cells. The microcomputer performs a correction of the concentration of the NOx detected by the sensor cell and a deterioration diagnosis of the sensor cell, based on the output change amounts ?Ip, ?Is, and ?Im of the cells. When the sensor cell current Is is smaller than the monitor cell current Im, the microcomputer determines that the NOx sensor has an abnormality.
    Type: Application
    Filed: December 11, 2017
    Publication date: April 19, 2018
    Inventors: Ryozo KAYAMA, Yukihiro YAMASHITA, Yoshihiro SAKASHITA
  • Publication number: 20170219513
    Abstract: A gas concentration detection device includes a pump cell, a sensor cell, a monitor cell, a sensor current detection unit detecting a current outputted by the sensor cell, a monitor current detection unit detecting a current outputted by the monitor cell, a voltage adjustment unit adjusting a pump cell voltage applied to the pump cell, and a sensitivity determination unit determining a gas sensitivity of at least one of the sensor cell or the monitor cell. The voltage adjustment unit changes the pump cell voltage from a target voltage into a detection voltage where the concentration of the residual oxygen supplied to the sensor cell and the monitor cell is increased. The sensitivity determination unit determines the gas sensitivity based on a detection current detected by at least one of the sensor current detection unit or the monitor current detection unit in accordance with the concentration of the residual oxygen.
    Type: Application
    Filed: July 24, 2015
    Publication date: August 3, 2017
    Applicant: DENSO CORPORATION
    Inventors: Ryozo KAYAMA, Yukihiro YAMASHITA
  • Publication number: 20170184536
    Abstract: An SCU as a control device for the gas sensor (first and second NOx sensors) includes an applied voltage switching unit for switching an applied voltage of a pump cell when a deterioration detecting function is performed, and a deterioration rate calculation unit for calculating a deterioration rate of a sensor cell based on a slope during a transient change in an output of the sensor cell according to a switching of the applied voltage by the applied voltage switching unit.
    Type: Application
    Filed: December 22, 2016
    Publication date: June 29, 2017
    Inventors: Yusuke KAWAMOTO, Toru KATAFUCHI, Takehito KIMATA, Ryozo KAYAMA
  • Publication number: 20170010236
    Abstract: An exhaust gas sensor includes a sensor element having a plurality of cells, and a heater heating the sensor element. A heater control device for the exhaust gas sensor includes a heater power control unit that performs an impedance control, in which an energization of the heater is controlled by detecting an impedance of one cell to be measured, of the plurality of cells, such that the impedance of the one cell agrees with a target impedance. The heater power control unit, in the impedance control, estimates a temperature of the other cell other than the one cell based on at least one parameter of an energization condition of the heater and an operating condition of the internal-combustion engine, and corrects the target impedance so that the temperature of the other cell becomes lower than or equal to a permissible upper limit temperature.
    Type: Application
    Filed: April 8, 2015
    Publication date: January 12, 2017
    Inventors: Yoshihiro SAKASHITA, Yukihiro YAMASHITA, Ryozo KAYAMA
  • Publication number: 20170009685
    Abstract: A heater control device for an exhaust gas sensor disposed in an exhaust gas passage of an internal combustion engine and including a sensor element having a plurality of cells, and a heater heating the sensor element includes: a heater power control unit configured to execute a temp rising control, in which an impedance of one cell to be measured, of the plurality of cells, is detected and a temperature of the sensor element is raised until the impedance of the one cell reaches a target impedance by setting a power control value of the heater as a heating power control value. The heater power control unit continues the temp rising control until an extension period elapses that is needed for the other cell other than the one cell to reach an activation temperature after the impedance of the one cell reaches the target impedance.
    Type: Application
    Filed: April 8, 2015
    Publication date: January 12, 2017
    Inventors: Yoshihiro SAKASHITA, Yukihiro YAMASHITA, Ryozo KAYAMA
  • Publication number: 20160223488
    Abstract: A NOx sensor includes a pump cell, a monitor cell, and a sensor cell, and the pump cell discharges an oxygen in an exhaust gas introduced into a chamber. The sensor cell outputs a detected signal depending on a concentration of a NOx according to a gas after the oxygen is discharged. A microcomputer of a sensor control circuit temporarily changes an amount of the oxygen discharged by the pump cell, and then calculates output change amounts ?Ip, ?Is, and ?Im of the cells. The microcomputer performs a correction of the concentration of the NOx detected by the sensor cell and a deterioration diagnosis of the sensor cell, based on the output change amounts ?Ip, ?Is, and ?Im of the cells. When the sensor cell current Is is smaller than the monitor cell current Im, the microcomputer determines that the NOx sensor has an abnormality.
    Type: Application
    Filed: September 11, 2014
    Publication date: August 4, 2016
    Inventors: Ryozo KAYAMA, Yukihiro YAMASHITA, Yoshihiro SAKASHITA
  • Patent number: 9222379
    Abstract: An electric control device includes: a cam having a variable distance between an outer periphery and a center; a control shaft having one end, which contacts the outer periphery of the cam, and displaceable according to a rotation of the cam to adjust a valve lift amount; a motor rotating the cam; an angle detector detecting a rotation angle of the cam; and a controller. The cam includes multiple steps arranged on the outer periphery. The controller controls the rotation of the cam through the motor to match a detection angle of the angle detector with a target angle corresponding to a target valve lift amount. The controller stops rotating the cam through the motor when a difference between the detection angle and the target angle exceeds a first threshold, and the target angle corresponds to one of the steps.
    Type: Grant
    Filed: May 14, 2014
    Date of Patent: December 29, 2015
    Assignee: DENSO CORPORATION
    Inventors: Atsushi Ito, Ryozo Kayama, Shinichi Sugiura, Yasuyoshi Suzuki