Patents by Inventor Mitsuo Hitomi

Mitsuo Hitomi 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: 11028797
    Abstract: The engine control method includes a fuel supply step and an ignition step. In the fuel supply step, the injector supplies fuel into a combustion chamber. In the ignition step, an spark plug arranged in the combustion chamber makes a flame after the supply of the fuel into the combustion chamber and at a timing when a flow strength in the combustion chamber is greater than a predetermined value in a compression stroke during or before a post-mid stage where the compression stroke is divided into four stages of a pre-stage, a pre-mid stage, a post-mid stage, and a post-stage.
    Type: Grant
    Filed: January 23, 2019
    Date of Patent: June 8, 2021
    Assignee: Mazda Motor Corporation
    Inventors: Mitsuo Hitomi, Eiji Nakai, Naohiro Yamaguchi, Hiroki Morimoto
  • Publication number: 20210033042
    Abstract: The engine control method includes a fuel supply step and an ignition step. In the fuel supply step, the injector supplies fuel into a combustion chamber. In the ignition step, an spark plug arranged in the combustion chamber makes a flame after the supply of the fuel into the combustion chamber and at a timing when a flow strength in the combustion chamber is greater than a predetermined value in a compression stroke during or before a post-mid stage where the compression stroke is divided into four stages of a pre-stage, a pre-mid stage, a post-mid stage, and a post-stage.
    Type: Application
    Filed: January 23, 2019
    Publication date: February 4, 2021
    Inventors: Mitsuo HITOMI, Eiji NAKAI, Naohiro YAMAGUCHI, Hiroki MORIMOTO
  • Publication number: 20210033038
    Abstract: An engine control method includes: a first fuel supply step of supplying fuel into the combustion chamber using an injector when a spark plug makes flame in the combustion chamber so that an air-fuel mixture is generated at least around the spark plug, the air-fuel mixture having an air-fuel mass ratio A/F or a gas-fuel mass ratio G/F, in which gas includes air, higher than a stoichiometric air-fuel ratio; after the first fuel supply step, an ignition step of making the flame in the combustion chamber in the compression stroke using the spark plug; and after the ignition step, a second fuel supply step of supplying the fuel into the combustion chamber in the compression stroke using the injector to increase a fuel concentration of the air-fuel mixture in the combustion chamber.
    Type: Application
    Filed: January 23, 2019
    Publication date: February 4, 2021
    Inventors: Mitsuo HITOMI, Eiji NAKAI, Naohiro YAMAGUCHI, Hiroki MORIMOTO
  • Publication number: 20200191071
    Abstract: A compression ignition engine includes: a naphtha injector for supplying naphtha to a combustion chamber; a diesel fuel injector for supplying diesel fuel having a higher boiling point than naphtha; an ignition device for assisting ignition of an air-fuel mixture; and a PCM connected to the naphtha injector, the diesel fuel injector, and the ignition device. When the diesel engine is cold, the PCM supplies only naphtha out of naphtha and diesel fuel, and assists ignition of an air-fuel mixture formed by naphtha.
    Type: Application
    Filed: May 29, 2018
    Publication date: June 18, 2020
    Inventors: Mitsuo Hitomi, Hiroyuki Yamamoto, Toshihide Yamamoto, Hidefumi Fujimoto
  • Publication number: 20200182175
    Abstract: Disclosed is a compression ignition engine including a first fuel supply supplying naphtha, a second fuel supply supplying diesel fuel, an EGR gas recirculation portion recirculating exhaust gas back to a combustion chamber, and a controller controlling these components. The controller determines whether an engine body is operated in a low load region or a high load region. In the low load region, the controller outputs a control signal to the first fuel supply so that at least naphtha is supplied, and outputs a control signal to the EGR gas recirculation portion such that an EGR rate becomes higher than that when the engine is operated in the high load region to make an air-fuel ratio fall within a range of 14.5 to 15.0.
    Type: Application
    Filed: May 29, 2018
    Publication date: June 11, 2020
    Inventors: Mitsuo Hitomi, Hiroyuki Yamamoto, Toshihide Yamamoto, Hidefumi Fujimoto
  • Publication number: 20200158030
    Abstract: A compression ignition engine includes an engine body, a first fuel supply for supplying a first fuel, a second fuel supply for supplying a second fuel, and a controller for outputting a signal to each of the first and second fuel supplies. The second fuel less easily vaporizes than the first fuel, and has a pressure and temperature at which compression ignition is initiated and at least one of which is lower than that of the first fuel. The controller outputs a signal to the first fuel supply such that a weight of the supplied first fuel is larger than that of the supplied second fuel, and thereafter, outputs a signal to the second fuel supply such that the second fuel is supplied to a combustion chamber. A formed air-fuel mixture is compressed and ignited.
    Type: Application
    Filed: May 29, 2018
    Publication date: May 21, 2020
    Inventors: Mitsuo Hitomi, Hiroyuki Yamamoto, Toshihide Yamamoto, Hidefumi Fujimoto
  • Patent number: 9328688
    Abstract: Various systems and methods are disclosed for controlling an internal combustion engine system having an internal combustion engine, a fuel injector which directly injects fuel into a combustion chamber of the internal combustion engine, and a supercharger which supercharges air into the combustion chamber. One example method comprises, injecting fuel into the combustion chamber multiple times so that a first part of the fuel is self ignited and a last part of the fuel being injected during the compression stroke or later in a cylinder cycle when a desired torque of said internal combustion engine system is in a first range; and increasing a pressure of air which the supercharger charges into the combustion chamber as amount of fuel injected into the combustion chamber during a cylinder cycle increases when the desired torque is in the first range.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: May 3, 2016
    Assignee: Mazda Motor Corporation
    Inventors: Mitsuo Hitomi, Masahisa Yamakawa, Toshiaki Nishimoto, Takashi Youso, Keiji Araki
  • Patent number: 8544444
    Abstract: Various systems and methods are disclosed for controlling an internal combustion engine system having an internal combustion engine, and a fuel injector which directly injects fuel into a combustion chamber of the internal combustion engine. One example method comprises, when a desired torque for the internal combustion engine system is in a first range, injecting a first stage fuel into the combustion chamber so that it ends during a middle stage of a compression stroke at the latest in a cylinder cycle; determining combustion of the first stage fuel initiated by its compression self-ignition; and injecting a second stage fuel into the combustion chamber in a period when the determined combustion of the first stage fuel continues at a timing determined so as to cause combustion of the second stage fuel with its compression self-ignition.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: October 1, 2013
    Assignee: Mazda Motor Corporation
    Inventors: Mitsuo Hitomi, Masahisa Yamakawa, Toshiaki Nishimoto, Takashi Youso, Keiji Araki
  • Patent number: 8468823
    Abstract: Disclosed is a supercharged direct-injection engine, which comprises a supercharging device (25, 30) for compressing intake air, and an injector 10 for directly injecting fuel into a combustion chamber 5. In the engine, an excess air factor ? as a ratio of an actual air-fuel ratio to a stoichiometric air-fuel ratio, at least in an engine warmed-up mode, is set to 2 or more in the entire engine-load region. Further, compressed self-ignited combustion is performed in a low engine-load region, and a supercharging amount by the supercharging device (25, 30) is increased along with an increase in engine load in a high engine-load region to allow the excess air factor ? to be kept at 2 or more. The engine of the present invention can effectively reduce NOx emission, while improving fuel economy.
    Type: Grant
    Filed: March 22, 2010
    Date of Patent: June 25, 2013
    Assignee: Mazda Motor Corporation
    Inventors: Mitsuo Hitomi, Masahisa Yamakawa, Takashi Youso, Toshiaki Nishimoto, Keiji Araki
  • Publication number: 20110067679
    Abstract: Disclosed is a supercharged direct-injection engine, which comprises a supercharging device (25, 30) for compressing intake air, and an injector 10 for directly injecting fuel into a combustion chamber 5. In the engine, an excess air factor ? as a ratio of an actual air-fuel ratio to a stoichiometric air-fuel ratio, at least in an engine warmed-up mode, is set to 2 or more in the entire engine-load region. Further, compressed self-ignited combustion is performed in a low engine-load region, and a supercharging amount by the supercharging device (25, 30) is increased along with an increase in engine load in a high engine-load region to allow the excess air factor ? to be kept at 2 or more. The engine of the present invention can effectively reduce NOx emission, while improving fuel economy.
    Type: Application
    Filed: March 22, 2010
    Publication date: March 24, 2011
    Applicant: MAZDA MOTOR CORPORATION
    Inventors: Mitsuo HITOMI, Masahisa YAMAKAWA, Takashi YOUSO, Toshiaki NISHIMOTO, Keiji ARAKI
  • Publication number: 20100242900
    Abstract: Various systems and methods are disclosed for controlling an internal combustion engine system having an internal combustion engine, and a fuel injector which directly injects fuel into a combustion chamber of the internal combustion engine. One example method comprises, when a desired torque for the internal combustion engine system is in a first range, injecting a first stage fuel into the combustion chamber so that it ends during a middle stage of a compression stroke at the latest in a cylinder cycle; determining combustion of the first stage fuel initiated by its compression self-ignition; and injecting a second stage fuel into the combustion chamber in a period when the determined combustion of the first stage fuel continues at a timing determined so as to cause combustion of the second stage fuel with its compression self-ignition.
    Type: Application
    Filed: March 29, 2010
    Publication date: September 30, 2010
    Applicant: MAZDA MOTOR CORPORATION
    Inventors: Mitsuo Hitomi, Masahisa Yamakawa, Toshiaki Nishimoto, Takashi Youso, Keiji Araki
  • Publication number: 20100242899
    Abstract: Various systems and methods are disclosed for controlling an internal combustion engine system having an internal combustion engine, a fuel injector which directly injects fuel into a combustion chamber of the internal combustion engine, and a supercharger which supercharges air into the combustion chamber. One example method comprises, injecting fuel into the combustion chamber multiple times so that a first part of the fuel is self ignited and a last part of the fuel being injected during the compression stroke or later in a cylinder cycle when a desired torque of said internal combustion engine system is in a first range; and increasing a pressure of air which the supercharger charges into the combustion chamber as amount of fuel injected into the combustion chamber during a cylinder cycle increases when the desired torque is in the first range.
    Type: Application
    Filed: March 29, 2010
    Publication date: September 30, 2010
    Applicant: MAZDA MOTOR CORPORATION
    Inventors: Mitsuo HITOMI, Masahisa YAMAKAWA, Toshiaki NISHIMOTO, Takashi YOUSO, Keiji ARAKI
  • Patent number: 7784443
    Abstract: A spark-ignition gasoline engine having at least a spark plug, the engine including an engine body having a geometrical compression ratio set at 14 or more, and an intake valve and an exhaust valve provided, respectively, in intake and exhaust ports connected to each of a plurality of cylinders of the engine body. The intake and exhaust valves are adapted to open and close corresponding respective ones of the intake and exhaust ports. The engine further includes an operation-state detector adapted to detect an operation state of the engine body and a control system adapted, based on detection of the operation-state detector, to perform at least an adjustment control of an ignition timing of the spark plug, the control system being operable, when an engine operation zone is a high-load operation zone including a wide open throttle region within at least a low speed range, to retard the ignition timing to a point within a predetermined stroke range just after a top dead center of a compression stroke.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: August 31, 2010
    Assignee: Mazda Motor Corporation
    Inventors: Mitsuo Hitomi, Noriyuki Iwata, Masahisa Yamakawa, Toshiaki Nishimoto, Takashi Yohso, Takayoshi Hayashi
  • Publication number: 20090159045
    Abstract: A spark-ignition gasoline engine having at least a spark plug, the engine including an engine body having a geometrical compression ratio set at 14 or more, and an intake valve and an exhaust valve provided, respectively, in intake and exhaust ports connected to each of a plurality of cylinders of the engine body. The intake and exhaust valves are adapted to open and close corresponding respective ones of the intake and exhaust ports. The engine further includes an operation-state detector adapted to detect an operation state of the engine body and a control system adapted, based on detection of the operation-state detector, to perform at least an adjustment control of an ignition timing of the spark plug, the control system being operable, when an engine operation zone is a high-load operation zone including a wide open throttle region within at least a low speed range, to retard the ignition timing to a point within a predetermined stroke range just after a top dead center of a compression stroke.
    Type: Application
    Filed: January 30, 2009
    Publication date: June 25, 2009
    Applicant: MAZDA MOTOR CORPORATION
    Inventors: Mitsuo Hitomi, Noriyuki Iwata, Masahisa Yamakawa, Toshiaki Nishimoto, Takashi Yohso, Takayoshi Hayashi
  • Patent number: 7484498
    Abstract: Disclosed is a spark-ignition gasoline engine, which comprises control means operable, when an engine operation zone is a high-load operation zone including a WOT region within at least a low speed range, to adjust a closing timing of an intake valve in such a manner as to maintain an effective compression ratio at 13 or more, and retard an ignition timing to a point within a predetermined stroke range just after a top dead center of a compression stroke, wherein the effective compression ratio is calculated based on an intake-valve closing timing defined by a valve lift amount of 1 mm. The present invention can provide a spark-ignition gasoline engine having both a low-cost performance and a high engine-power performance even in a high-load operation zone (particularly WOT region) in a low speed range.
    Type: Grant
    Filed: March 28, 2007
    Date of Patent: February 3, 2009
    Assignee: Mazda Motor Corporation
    Inventors: Mitsuo Hitomi, Noriyuki Iwata, Masahisa Yamakawa, Toshiaki Nishimoto, Takashi Yohso, Takayoshi Hayashi
  • Publication number: 20070227503
    Abstract: Disclosed is a spark-ignition gasoline engine, which comprises control means operable, when an engine operation zone is a high-load operation zone including a WOT region within at least a low speed range, to adjust a closing timing of an intake valve in such a manner as to maintain an effective compression ratio at 13 or more, and retard an ignition timing to a point within a predetermined stroke range just after a top dead center of a compression stroke, wherein the effective compression ratio is calculated based on an intake-valve closing timing defined by a valve lift amount of 1 mm. The present invention can provide a spark-ignition gasoline engine having both a low-cost performance and a high engine-power performance even in a high-load operation zone (particularly WOT region) in a low speed range.
    Type: Application
    Filed: March 28, 2007
    Publication date: October 4, 2007
    Inventors: Mitsuo Hitomi, Noriyuki Iwata, Masahisa Yamakawa, Toshiaki Nishimoto, Takashi Yohso, Takayoshi Hayashi
  • Patent number: 7237511
    Abstract: There are provided a radiator passage, a thermostat to open and close the radiator passage according to an engine temperature, a heater passage, a flow adjusting device to adjust a flow amount of the coolant that flows in the water jacket according to the engine temperature at an engine start. The flow adjusting device is configured so as to adjust the flow amount of the coolant flowing in the water jacket to be a normal amount when the engine temperature is in an extremely-cold condition, to be zero or smaller than the normal amount when the engine is in a mild-cold condition, and to be the normal amount when the engine is in a warm condition. The heater passage is in opened sate at least when the engine is in the extremely-cold condition.
    Type: Grant
    Filed: February 22, 2006
    Date of Patent: July 3, 2007
    Assignee: Mazda Motor Corporation
    Inventors: Akinobu Aoki, Mitsuo Hitomi
  • Patent number: 7219634
    Abstract: For the purpose of improving the fuel efficiency by lean combustion and enhancing the fuel efficiency improvement effects by performing compression ignition efficiently in some cylinders, a multi-cylinder spark ignition engine is constructed such that exhaust gas, that is exhausted from preceding cylinders 2A, 2D on the exhaust stroke side among pairs of cylinders whose exhaust stroke and intake stroke overlap in a low load, low rotational speed region, is directly introduced through an inter-cylinder gas passage 22 into following cylinders 2B, 2C on the intake stroke side and only gas exhausted from the following cylinders 2B, 2C is fed to an exhaust passage 20, which is provided with a three-way catalyst 24.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: May 22, 2007
    Assignee: Mazda Motor Corporation
    Inventors: Mitsuo Hitomi, Toshiaki Nishimoto, Yoshiyuki Shinya, Kouji Sumida, Takayoshi Hayashi, Noriyuki Iwata, Kouji Asanomi, Taketoshi Yamauchi, Keiji Araki
  • Patent number: 7182050
    Abstract: The invention is intended to provide improved emission-cleaning performance by use of a three-way catalyst alone, without the need for a lean NOx catalyst, while ensuring a fuel economy improvement effect of lean burn operation. A multicylinder spark-ignition engine is constructed such that, in a pair of preceding and following cylinders whose exhaust and intake strokes overlap each other, burned gas discharged from the preceding cylinder (2A, 2D) which is currently in the exhaust stroke is introduced directly into the following cylinder (2B, 2C) which is currently in the intake stroke through an intercylinder gas channel (22) and gas discharged from only the following cylinder (2B, 2C) is led to an exhaust passage (20) provided with a three-way catalyst (24) in a low-load, low-speed operating range.
    Type: Grant
    Filed: January 31, 2003
    Date of Patent: February 27, 2007
    Assignee: Mazda Motor Corporation
    Inventors: Mitsuo Hitomi, Taketoshi Yamauchi, Yoshiyuki Shinya, Kouji Sumida, Takayoshi Hayashi
  • Publication number: 20060213460
    Abstract: There are provided a radiator passage, a thermostat to open and close the radiator passage according to an engine temperature, a heater passage, a flow adjusting device to adjust a flow amount of the coolant that flows in the water jacket according to the engine temperature at an engine start. The flow adjusting device is configured so as to adjust the flow amount of the coolant flowing in the water jacket to be a normal amount when the engine temperature is in an extremely-cold condition, to be zero or smaller than the normal amount when the engine is in a mild-cold condition, and to be the normal amount when the engine is in a warm condition. The heater passage is in opened sate at least when the engine is in the extremely-cold condition.
    Type: Application
    Filed: February 22, 2006
    Publication date: September 28, 2006
    Applicant: MAZDA MOTOR CORPORATION
    Inventors: Akinobu Aoki, Mitsuo Hitomi