Patents by Inventor Kota Maekawa

Kota Maekawa 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: 10900460
    Abstract: A control system for a compression-ignition engine includes a combustion chamber, an injector, an ignition plug, a sensor device, and a controller having a circuitry. The ignition plug forcibly ignites mixture gas to start combustion accompanied by flame propagation of a part of the mixture gas, and again ignites remaining unburnt mixture gas at a timing at which the unburnt mixture gas combusts by self-ignition. The controller is configured to execute an ignition controlling module to output an ignition signal to the ignition plug before a target timing so that the unburnt mixture gas self-ignites at the target timing, an ignition timing estimating module to estimate an actual CI timing indicative of a timing at which the unburnt mixture gas actually self-ignited based on an in-cylinder pressure parameter, and an in-cylinder temperature determining module to determine the in-cylinder temperature at a given crank angle based on the estimated result.
    Type: Grant
    Filed: June 24, 2019
    Date of Patent: January 26, 2021
    Assignee: Mazda Motor Corporation
    Inventors: Kota Maekawa, Kyotaro Nishimoto, Yuichiro Tsumura, Kenko Ujihara
  • Patent number: 10876485
    Abstract: An engine control device is provided, which includes an ignition plug configured to ignite mixture gas inside a cylinder of the engine, an injector configured to change an air-fuel ratio inside the cylinder, a NOx sensor, and a controller including a processor. The controller performs a first control to control the ignition plug so that ignition is performed at a basic ignition timing or an ignition timing after the basic timing is corrected based on a combustion state of the mixture gas, and a second control to control the injector so that a NOx concentration approaches a given target value. When the ignition timing is corrected by the first control to a retarding side, the controller suspends a correction to a richer side even if the NOx concentration is a concentration at which the air-fuel ratio is corrected to the richer side by the second control.
    Type: Grant
    Filed: October 2, 2019
    Date of Patent: December 29, 2020
    Assignee: Mazda Motor Corporation
    Inventors: Kota Maekawa, Takeatsu Ito, Kouji Miyamoto
  • Patent number: 10830186
    Abstract: A premixed compression ignition engine system includes an engine, a fuel injector, a water injector, and a controller. The controller conducts: a compression-stroke mid-period injection that causes a fuel injector to inject fuel to form a fuel-air mixture in a surrounding space of a combustion chamber; a compression top-dead-center injection that causes the fuel injector to inject fuel to form a fuel-air mixture in the central space of the combustion chamber after the compression-stroke mid-period injection; and a water injection that causes a water injector to inject water to the surrounding space of the combustion chamber at a timing from commencement of the compression-stroke mid-period injection to commencement of the compression top-dead-center injection.
    Type: Grant
    Filed: October 5, 2017
    Date of Patent: November 10, 2020
    Assignee: Mazda Motor Corporation
    Inventors: Tohru Hokazono, Kota Maekawa, Yoshihisa Nakamoto, Masaharu Marumoto, Yusuke Koike, Ryohei Ono
  • Publication number: 20200141344
    Abstract: An engine control device is provided, which includes an ignition plug configured to ignite mixture gas inside a cylinder of the engine, an injector configured to change an air-fuel ratio inside the cylinder, a NOx sensor, and a controller including a processor. The controller performs a first control to control the ignition plug so that ignition is performed at a basic ignition timing or an ignition timing after the basic timing is corrected based on a combustion state of the mixture gas, and a second control to control the injector so that a NOx concentration approaches a given target value. When the ignition timing is corrected by the first control to a retarding side, the controller suspends a correction to a richer side even if the NOx concentration is a concentration at which the air-fuel ratio is corrected to the richer side by the second control.
    Type: Application
    Filed: October 2, 2019
    Publication date: May 7, 2020
    Inventors: Kota Maekawa, Takeatsu Ito, Kouji Miyamoto
  • Publication number: 20200141345
    Abstract: An engine control device is provided, which includes an engine body where a cylinder is formed, an exhaust passage through which exhaust gas discharged from the engine body circulates, a NOx sensor disposed in the exhaust passage and configured to detect a concentration of NOx in the exhaust gas, an injector configured to change an air-fuel ratio inside the cylinder, an in-cylinder temperature changer configured to change a temperature inside the cylinder, and a controller configured to control the injector and the exhaust shutter valve. The controller controls the injector based on a detection value of the NOx sensor to variably set the air-fuel ratio inside the cylinder, and when a particular condition that the air-fuel ratio inside the cylinder is leaner than a preset upper limit is satisfied, and causes the in-cylinder temperature changer to raise the temperature inside the cylinder.
    Type: Application
    Filed: October 25, 2019
    Publication date: May 7, 2020
    Inventors: Kota Maekawa, Takeatsu Ito, Tomokuni Kusunoki, Keitaro Ezumi
  • Publication number: 20200040850
    Abstract: A premixed compression ignition engine system includes an engine, a fuel injector, a water injector, and a controller. The controller conducts: a compression-stroke mid-period injection that causes a fuel injector to inject fuel to form a fuel-air mixture in a surrounding space of a combustion chamber; a compression top-dead-center injection that causes the fuel injector to inject fuel to form a fuel-air mixture in the central space of the combustion chamber after the compression-stroke mid-period injection; and a water injection that causes a water injector to inject water to the surrounding space of the combustion chamber at a timing from commencement of the compression-stroke mid-period injection to commencement of the compression top-dead-center injection.
    Type: Application
    Filed: October 5, 2017
    Publication date: February 6, 2020
    Inventors: Tohru Hokazono, Kota Maekawa, Yoshihisa Nakamoto, Masaharu Marumoto, Yusuke Koike, Ryohei Ono
  • Publication number: 20200032761
    Abstract: A control system for a compression-ignition engine includes a combustion chamber, an injector, an ignition plug, a sensor device, and a controller having a circuitry. The ignition plug forcibly ignites mixture gas to start combustion accompanied by flame propagation of a part of the mixture gas, and again ignites remaining unburnt mixture gas at a timing at which the unburnt mixture gas combusts by self-ignition. The controller is configured to execute an ignition controlling module to output an ignition signal to the ignition plug before a target timing so that the unburnt mixture gas self-ignites at the target timing, an ignition timing estimating module to estimate an actual CI timing indicative of a timing at which the unburnt mixture gas actually self-ignited based on an in-cylinder pressure parameter, and an in-cylinder temperature determining module to determine the in-cylinder temperature at a given crank angle based on the estimated result.
    Type: Application
    Filed: June 24, 2019
    Publication date: January 30, 2020
    Inventors: Kota Maekawa, Kyotaro Nishimoto, Yuichiro Tsumura, Kenko Ujihara
  • Patent number: 9863350
    Abstract: When a predetermined restart condition is satisfied after an engine is automatically stopped, whether or not a piston of a stopped-in-compression-stroke cylinder which is in a compression stroke falls within a specific range set at a bottom dead center side of a predetermined upper limit position is determined. When the piston of the stopped-in-compression-stroke cylinder falls within the specific range, a first compression start is executed in which fuel is injected from an injector into the stopped-in-compression-stroke cylinder for the first time and is then self-ignited. In the first compression start, a start timing of a first fuel injection operation with respect to the stopped-in-compression-stroke cylinder is set to be earlier as a stop position of the piston of the cylinder gets closer to the bottom dead center within the specific range.
    Type: Grant
    Filed: April 24, 2014
    Date of Patent: January 9, 2018
    Assignee: Mazda Motor Corporation
    Inventors: Yoshihisa Nakamoto, Kota Maekawa
  • Patent number: 9464585
    Abstract: An exhaust gas recirculation control device of an engine is provided. The device includes: an exhaust turbocharger having a turbine disposed in an exhaust passage and a compressor disposed in an intake passage; a low-pressure EGR passage connecting a part of the exhaust passage downstream of the turbine to a part of the intake passage upstream of the compressor; a low-pressure EGR valve disposed in the low-pressure EGR passage and for changing a cross-sectional area of the low-pressure EGR passage; an exhaust shutter valve disposed downstream of the connected part of the exhaust passage to the low-pressure EGR passage, and for changing a cross-sectional area of the exhaust passage; a valve control device for controlling openings of the low-pressure EGR valve and the exhaust shutter valve; and a gear range detector for detecting a gear range of a transmission of a vehicle in which the engine is installed.
    Type: Grant
    Filed: August 27, 2014
    Date of Patent: October 11, 2016
    Assignee: Mazda Motor Corporation
    Inventors: Kenji Tanimura, Kota Maekawa, Eiji Nakai, Motoshi Kataoka, Masanobu Kanno
  • Patent number: 9464586
    Abstract: An exhaust gas recirculation control device of an engine is provided. The device includes: an exhaust turbocharger having a turbine disposed in an exhaust passage and a compressor disposed in an intake passage; an intercooler disposed in the intake passage downstream of the compressor; a low-pressure EGR passage connecting the exhaust passage downstream of the turbine to the intake passage upstream of the compressor; a low-pressure EGR valve disposed in the low-pressure EGR passage and for changing a cross-sectional area thereof; a high-pressure EGR passage connecting the exhaust passage upstream of the turbine to the intake passage downstream of the intercooler; a high-pressure EGR valve disposed in the high-pressure EGR passage and for changing a cross-sectional area thereof; a valve control device for controlling openings of the low-pressure and high-pressure EGR valves; and a gear range detector for detecting a gear range of a transmission.
    Type: Grant
    Filed: August 27, 2014
    Date of Patent: October 11, 2016
    Assignee: Mazda Motor Corporation
    Inventors: Kota Maekawa, Kenji Tanimura, Eiji Nakai, Motoshi Kataoka, Masanobu Kanno
  • Publication number: 20160076472
    Abstract: When a predetermined restart condition is satisfied after an engine is automatically stopped, whether or not a piston of a stopped-in-compression-stroke cylinder which is in a compression stroke falls within a specific range set at a bottom dead center side of a predetermined upper limit position is determined. When the piston of the stopped-in-compression-stroke cylinder falls within the specific range, a first compression start is executed in which fuel is injected from an injector into the stopped-in-compression-stroke cylinder for the first time and is then self-ignited. In the first compression start, a start timing of a first fuel injection operation with respect to the stopped-in-compression-stroke cylinder is set to be earlier as a stop position of the piston of the cylinder gets closer to the bottom dead center within the specific range.
    Type: Application
    Filed: April 24, 2014
    Publication date: March 17, 2016
    Inventors: Yoshihisa Nakamoto, Kota Maekawa
  • Publication number: 20150089941
    Abstract: An exhaust gas recirculation control device of an engine is provided. The device includes: an exhaust turbocharger having a turbine disposed in an exhaust passage and a compressor disposed in an intake passage; an intercooler disposed in the intake passage downstream of the compressor; a low-pressure EGR passage connecting the exhaust passage downstream of the turbine to the intake passage upstream of the compressor; a low-pressure EGR valve disposed in the low-pressure EGR passage and for changing a cross-sectional area thereof; a high-pressure EGR passage connecting the exhaust passage upstream of the turbine to the intake passage downstream of the intercooler; a high-pressure EGR valve disposed in the high-pressure EGR passage and for changing a cross-sectional area thereof; a valve control device for controlling openings of the low-pressure and high-pressure EGR valves; and a gear range detector for detecting a gear range of a transmission.
    Type: Application
    Filed: August 27, 2014
    Publication date: April 2, 2015
    Inventors: Kota Maekawa, Kenji Tanimura, Eiji Nakai, Motoshi Kataoka, Masanobu Kanno
  • Publication number: 20150089938
    Abstract: An exhaust gas recirculation control device of an engine is provided. The device includes: an exhaust turbocharger having a turbine disposed in an exhaust passage and a compressor disposed in an intake passage; a low-pressure EGR passage connecting a part of the exhaust passage downstream of the turbine to a part of the intake passage upstream of the compressor; a low-pressure EGR valve disposed in the low-pressure EGR passage and for changing a cross-sectional area of the low-pressure EGR passage; an exhaust shutter valve disposed downstream of the connected part of the exhaust passage to the low-pressure EGR passage, and for changing a cross-sectional area of the exhaust passage; a valve control device for controlling openings of the low-pressure EGR valve and the exhaust shutter valve; and a gear range detector for detecting a gear range of a transmission of a vehicle in which the engine is installed.
    Type: Application
    Filed: August 27, 2014
    Publication date: April 2, 2015
    Inventors: Kenji Tanimura, Kota Maekawa, Eiji Nakai, Motoshi Kataoka, Masanobu Kanno
  • Publication number: 20100250103
    Abstract: An exemplary method of controlling an internal combustion engine system is described herein. The internal combustion engine system includes an internal combustion engine, a valve driving mechanism which reciprocally drives an intake valve and an exhaust valve for a combustion chamber of the internal combustion engine, a turbocharger including a turbine and a compressor, and a first EGR passage which communicates an exhaust passage downstream of the emission control device and an intake passage upstream of the compressor. The exemplary method includes shutting off supplying fuel to the combustion chamber under a predetermined condition, and decreasing a lift of the intake or exhaust valve for the combustion chamber during the shutting off supplying fuel to the combustion chamber compared to in a case of supplying fuel to said combustion chamber.
    Type: Application
    Filed: March 25, 2010
    Publication date: September 30, 2010
    Applicant: MAZDA MOTOR CORPORATION
    Inventors: Daisuke Shimo, Motoshi Kataoka, Yoshihisa Nakamoto, Tatsuya Tanaka, Kota Maekawa, Hideya Horii, Takashi Hatano