Patents by Inventor Hirokatsu Imagawa

Hirokatsu Imagawa 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: 11850540
    Abstract: An exhaust gas purification filter includes a plurality of cells each extending from an inflow end face to an outflow end face, a porous partition wall forming the cells in a partitioned manner, inflow-side sealing parts sealing openings on an inflow end face side of outflow cells where the exhaust gas flows out, and outflow-side sealing parts sealing openings on an outflow end face side of inflow cells where the exhaust gas flows in. Each of the inflow-side sealing parts has a porosity of less than 60%. The partition wall has a porosity of 60% or more and 70% or less. Assuming a pore size, at which cumulative pore volume is 50% in pore size distribution of the inflow-side sealing parts, is d50Pin, and a pore size, at which cumulative pore volume is 50% in pore size distribution of the partition wall, is d50B, the pore size d50Pin is less than 18 ?m, and the pore size d50B is 18 ?m or more and 25 ?m or less.
    Type: Grant
    Filed: October 21, 2021
    Date of Patent: December 26, 2023
    Assignee: DENSO CORPORATION
    Inventor: Hirokatsu Imagawa
  • Patent number: 11619154
    Abstract: In an exhaust gas purification filter, a partition wall has communicating pores. Each communicating pore has a surface opening on the gas-inflow-side surface and a plurality of portions, each portion having a diameter being reduced and then increased from the surface opening, one of the portions, whose diameter is the smallest, being defined as an inlet neck portion. As viewed in cross section in a thickness direction of the partition wall, the surface opening of each communication pore has a diameter defined as a surface opening diameter, the inlet neck portion of each communication pore has a diameter defined as an inlet neck diameter. The inlet neck diameter is smaller than the surface opening diameter, and an average value of the inlet neck diameters is 15 ?m or less. A surface opening ratio of the communicating pores in plan view of the gas-inflow-side partition wall surface is 40% or more.
    Type: Grant
    Filed: November 10, 2021
    Date of Patent: April 4, 2023
    Assignee: DENSO CORPORATION
    Inventor: Hirokatsu Imagawa
  • Publication number: 20220065146
    Abstract: In an exhaust gas purification filter, a partition wall has communicating pores. Each communicating pore has a surface opening on the gas-inflow-side surface and a plurality of portions, each portion having a diameter being reduced and then increased from the surface opening, one of the portions, whose diameter is the smallest, being defined as an inlet neck portion. As viewed in cross section in a thickness direction of the partition wall, the surface opening of each communication pore has a diameter defined as a surface opening diameter, the inlet neck portion of each communication pore has a diameter defined as an inlet neck diameter. The inlet neck diameter is smaller than the surface opening diameter, and an average value of the inlet neck diameters is 15 ?m or less. A surface opening ratio of the communicating pores in plan view of the gas-inflow-side partition wall surface is 40% or more.
    Type: Application
    Filed: November 10, 2021
    Publication date: March 3, 2022
    Inventor: Hirokatsu IMAGAWA
  • Publication number: 20220040624
    Abstract: An exhaust gas purification filter includes a plurality of cells each extending from an inflow end face to an outflow end face, a porous partition wall forming the cells in a partitioned manner, inflow-side sealing parts sealing openings on an inflow end face side of outflow cells where the exhaust gas flows out, and outflow-side sealing parts sealing openings on an outflow end face side of inflow cells where the exhaust gas flows in. Each of the inflow-side sealing parts has a porosity of less than 60%. The partition wall has a porosity of 60% or more and 70% or less. Assuming a pore size, at which cumulative pore volume is 50% in pore size distribution of the inflow-side sealing parts, is d50Pin, and a pore size, at which cumulative pore volume is 50% in pore size distribution of the partition wall, is d50B, the pore size d50Pin is less than 18 ?m, and the pore size d50B is 18 ?m or more and 25 ?m or less.
    Type: Application
    Filed: October 21, 2021
    Publication date: February 10, 2022
    Inventor: Hirokatsu IMAGAWA
  • Patent number: 11231354
    Abstract: A method of manufacturing a particulate matter detection element for detecting particulate matter in a gas to be measured includes manufacturing flat-shaped conductor layers, flat-shaped insulating layers, a laminated structure in which the conductor layers and the insulating layers are alternately laminated, and a detecting unit having the conductor layers of different polarities as a pair of detection electrodes on a cross section of the laminated structure. The conductor layers each have a constant thickness, and include conductor layer planar portions having a stripped-pattern cross section, and tapered conductor layer end edge portions each having a triangular cross section, provided on both sides of the respective conductor layer planar portions.
    Type: Grant
    Filed: November 19, 2019
    Date of Patent: January 25, 2022
    Assignee: DENSO CORPORATION
    Inventors: Kazuhiko Koike, Hirokatsu Imagawa
  • Patent number: 10905992
    Abstract: A honeycomb structural body includes: a porous cell wall that partitions a cylindrical casing; and a large number of cells extending in the axial direction X thereof and alternately blocked at an upstream end face. The large number of cells include plugged cells having plugs and penetrating cells that do not have the plugs. The plugged cells and the penetrating cells both include complete cells and incomplete cells. At least some of plugged incomplete cells of the incomplete cells have a cross-sectional area smaller than a cross-sectional area of penetrating complete cells, and are configured as blocked cells that are entirely blocked inside in the axial direction.
    Type: Grant
    Filed: September 26, 2017
    Date of Patent: February 2, 2021
    Assignee: DENSO CORPORATION
    Inventors: Hirokatsu Imagawa, Hironori Niwa
  • Patent number: 10837878
    Abstract: A particulate matter detection sensor includes a particulate matter detection unit for changing the output of an electrical signal in accordance with change in the electrical characteristics due to the deposition of particulate matter contained in an exhaust gas G discharged from an internal combustion engine, and a cover member having a cylindrical cover wall and disposed to surround the particulate matter detection unit. The particulate matter detection unit includes a deposition portion on which a part of the particulate matter is deposited, and a plurality of detection electrodes disposed being spaced apart from each other on the deposition portion. The deposition portion of the particulate matter detection unit is arranged so as to be oriented towards the tip side of the cover member. The cover wall of the cover member includes a plurality of exhaust gas introduction holes formed at positions closer to the tip side than is the deposition portion.
    Type: Grant
    Filed: June 2, 2015
    Date of Patent: November 17, 2020
    Assignee: DENSO CORPORATION
    Inventors: Kazuhiko Koike, Masayuki Tamura, Hirokatsu Imagawa
  • Patent number: 10627312
    Abstract: A particulate matter sensor and a particulate matter sensing system using such a sensor are provided which are capable of being produced at decreased cost and accurately measuring the temperature of a heater. The particulate matter sensor includes a deposition portion on which particulate matter contained in exhaust gas is accumulated, a pair of electrodes which are disposed on the deposition portion and separate from each other, a heater which heats the deposition portion, and a pair of heater leads which form a path through which electrical current is delivered to the heater. A sensing line is connected to at least one of the heater leads to measure a resistance of the heater lead.
    Type: Grant
    Filed: June 8, 2016
    Date of Patent: April 21, 2020
    Assignee: DENSO CORPORATION
    Inventors: Go Miyagawa, Kouji Andoh, Masayuki Tamura, Hirokatsu Imagawa, Takao Mishima, Hideki Yamada, Masahiro Yamamoto
  • Publication number: 20200080923
    Abstract: A method of manufacturing a particulate matter detection element for detecting particulate matter in a gas to be measured includes manufacturing flat-shaped conductor layers, flat-shaped insulating layers, a laminated structure in which the conductor layers and the insulating layers are alternately laminated, and a detecting unit having the conductor layers of different polarities as a pair of detection electrodes on a cross section of the laminated structure. The conductor layers each have a constant thickness, and include conductor layer planar portions having a stripped-pattern cross section, and tapered conductor layer end edge portions each having a triangular cross section, provided on both sides of the respective conductor layer planar portions.
    Type: Application
    Filed: November 19, 2019
    Publication date: March 12, 2020
    Applicant: DENSO CORPORATION
    Inventors: Kazuhiko KOIKE, Hirokatsu IMAGAWA
  • Patent number: 10520415
    Abstract: A particulate matter detection element for detecting particulate matter in a gas to be measured includes flat-shaped conductor layers, flat-shaped insulating layers, a laminated structure in which the conductor layers and the insulating layers are alternately laminated, and a detecting unit having the conductor layers of different polarities as a pair of detection electrodes on a cross section of the laminated structure. The conductor layers each have a constant thickness, and include conductor layer planar portions having a stripped-pattern cross section, and tapered conductor layer end edge portions each having a triangular cross section, provided on both sides of the respective conductor layer planar portions.
    Type: Grant
    Filed: January 9, 2015
    Date of Patent: December 31, 2019
    Assignee: DENSO CORPORATION
    Inventors: Kazuhiko Koike, Hirokatsu Imagawa
  • Publication number: 20190224606
    Abstract: A honeycomb structural body includes: a porous cell wall that partitions a cylindrical casing; and a large number of cells extending in the axial direction X thereof and alternately blocked at an upstream end face. The large number of cells include plugged cells having plugs and penetrating cells that do not have the plugs. The plugged cells and the penetrating cells both include complete cells and incomplete cells. At least some of plugged incomplete cells of the incomplete cells have a cross-sectional area smaller than a cross-sectional area of penetrating complete cells, and are configured as blocked cells that are entirely blocked inside in the axial direction.
    Type: Application
    Filed: September 26, 2017
    Publication date: July 25, 2019
    Inventors: Hirokatsu IMAGAWA, Hironori NIWA
  • Publication number: 20190078991
    Abstract: A particulate matter detection element for detecting particulate matter in a gas to be measured includes flat-shaped conductor layers, flat-shaped insulating layers, a laminated structure in which the conductor layers and the insulating layers are alternately laminated, and a detecting unit having the conductor layers of different polarities as a pair of detection electrodes on a cross section of the laminated structure. The conductor layers each have a constant thickness, and include conductor layer planar portions having a stripped-pattern cross section, and tapered conductor layer end edge portions each having a triangular cross section, provided on both sides of the respective conductor layer planar portions.
    Type: Application
    Filed: November 15, 2018
    Publication date: March 14, 2019
    Inventors: Kazuhiko KOIKE, Hirokatsu IMAGAWA
  • Patent number: 10208643
    Abstract: A particulate matter detection apparatus includes a particulate matter quantity detection means, a temperature detection means that detects the temperature of exhaust gas, a control unit and a heating means. The particulate matter quantity detection means includes a particulate matter deposition portion that deposits thereon part of particulate matter contained in the exhaust gas emitted from an internal combustion engine and a pair of opposite electrodes arranged apart from each other on the particulate matter deposition portion. The control unit determines a deposition quantity of the particulate matter on the particulate matter deposition portion based on an electrical signal outputted by the particulate matter quantity detection means and receives information on the temperature of the exhaust gas detected by the temperature detection means. The control unit controls the heating means to heat the particulate matter deposition portion to 300° C.-800° C. during a cold start of the internal combustion engine.
    Type: Grant
    Filed: June 12, 2015
    Date of Patent: February 19, 2019
    Assignee: DENSO CORPORATION
    Inventors: Go Miyagawa, Hirokatsu Imagawa, Masayuki Tamura
  • Publication number: 20180195933
    Abstract: A particulate matter sensor and a particulate matter sensing system using such a sensor are provided which are capable of being produced at decreased cost and accurately measuring the temperature of a heater. The particulate matter sensor includes a deposition portion on which particulate matter contained in exhaust gas is accumulated, a pair of electrodes which are disposed on the deposition portion and separate from each other, a heater which heats the deposition portion, and a pair of heater leads which form a path through which electrical current is delivered to the heater. A sensing line is connected to at least one of the heater leads to measure a resistance of the heater lead.
    Type: Application
    Filed: June 8, 2016
    Publication date: July 12, 2018
    Inventors: Go MIYAGAWA, Kouji ANDOH, Masayuki TAMURA, Hirokatsu IMAGAWA, Takao MISHIMA, Hideki YAMADA, Masahiro YAMAMOTO
  • Publication number: 20170131185
    Abstract: A particulate matter detection sensor includes a particulate matter detection unit for changing the output of an electrical signal in accordance with change in the electrical characteristics due to the deposition of particulate matter contained in an exhaust gas G discharged from an internal combustion engine, and a cover member having a cylindrical cover wall and disposed to surround the particulate matter detection unit. The particulate matter detection unit includes a deposition portion on which a part of the particulate matter is deposited, and a plurality of detection electrodes disposed being spaced apart from each other on the deposition portion. The deposition portion of the particulate matter detection unit is arranged so as to be oriented towards the tip side of the cover member. The cover wall of the cover member includes a plurality of exhaust gas introduction holes formed at positions closer to the tip side than is the deposition portion.
    Type: Application
    Filed: June 2, 2015
    Publication date: May 11, 2017
    Inventors: Kazuhiko KOIKE, Masayuki TAMURA, Hirokatsu IMAGAWA
  • Publication number: 20170122179
    Abstract: A particulate matter detection apparatus includes a particulate matter quantity detection means, a temperature detection means that detects the temperature of exhaust gas, a control unit and a heating means. The particulate matter quantity detection means includes a particulate matter deposition portion that deposits thereon part of particulate matter contained in the exhaust gas emitted from an internal combustion engine and a pair of opposite electrodes arranged apart from each other on the particulate matter deposition portion. The control unit determines a deposition quantity of the particulate matter on the particulate matter deposition portion based on an electrical signal outputted by the particulate matter quantity detection means and receives information on the temperature of the exhaust gas detected by the temperature detection means. The control unit controls the heating means to heat the particulate matter deposition portion to 300° C.-800° C. during a cold start of the internal combustion engine.
    Type: Application
    Filed: June 12, 2015
    Publication date: May 4, 2017
    Inventors: Go MIYAGAWA, Hirokatsu IMAGAWA, Masayuki TAMURA
  • Publication number: 20160334321
    Abstract: A particulate matter detection element for detecting particulate matter in a gas to be measured includes flat-shaped conductor layers, flat-shaped insulating layers, a laminated structure in which the conductor layers and the insulating layers are alternately laminated, and a detecting unit having the conductor layers of different polarities as a pair of detection electrodes on a cross section of the laminated structure. The conductor layers each have a constant thickness, and include conductor layer planar portions having a stripped-pattern cross section, and tapered conductor layer end edge portions each having a triangular cross section, provided on both sides of the respective conductor layer planar portions.
    Type: Application
    Filed: January 9, 2015
    Publication date: November 17, 2016
    Inventors: Kazuhiko KOIKE, Hirokatsu IMAGAWA
  • Patent number: 8828206
    Abstract: In a gas sensor element, a measurement gas is introduced to a measurement electrode through a porous diffusion-resistant layer. A catalyst layer is formed on an outer surface of the diffusion-resistant layer via which the measurement gas flows into the diffusion-resistant layer. In the catalyst layer, the percentage content of Pt is in the range of 2.5 to 12 mass %, the percentage content of Pd is in the range of 0.4 to 2 mass %, and the percentage content of Rh is in the range of 0.06 to 1.5 mass %. The catalyst layer includes catalytic noble metal particles each of which is made of an alloy that contains at least Pt. For each of the catalytic noble metal particles, the percentage content of Pt at an outer peripheral portion of the catalytic noble metal particle is lower than that at a core portion of the catalytic noble metal particle.
    Type: Grant
    Filed: June 1, 2012
    Date of Patent: September 9, 2014
    Assignee: Denso Corporation
    Inventor: Hirokatsu Imagawa
  • Publication number: 20120305397
    Abstract: In a gas sensor element, a measurement gas is introduced to a measurement electrode through a porous diffusion-resistant layer. A catalyst layer is formed on an outer surface of the diffusion-resistant layer via which the measurement gas flows into the diffusion-resistant layer. In the catalyst layer, the percentage content of Pt is in the range of 2.5 to 12 mass %, the percentage content of Pd is in the range of 0.4 to 2 mass %, and the percentage content of Rh is in the range of 0.06 to 1.5 mass %. The catalyst layer includes catalytic noble metal particles each of which is made of an alloy that contains at least Pt. For each of the catalytic noble metal particles, the percentage content of Pt at an outer peripheral portion of the catalytic noble metal particle is lower than that at a core portion of the catalytic noble metal particle.
    Type: Application
    Filed: June 1, 2012
    Publication date: December 6, 2012
    Applicant: DENSO CORPORATION
    Inventor: Hirokatsu IMAGAWA
  • Publication number: 20110089032
    Abstract: A gas sensor element is disclosed which includes a solid electrolyte body, a measurement electrode, a reference electrode, a porous diffusion-resistant layer, a catalyst layer, and a plurality of protective layers. The catalyst layer is provided on an outer surface of the porous diffusion-resistant layer through which a measurement gas is introduced to the measurement electrode. The catalyst layer is comprised of a noble metal catalyst and catalyst-supporting particles. The protective layers are provided in layers on the catalyst layer and comprised of oxide particles. The average particle diameter of the catalyst-supporting particles of the catalyst layer is less than or equal to the average particle diameter of the oxide particles of the one of the protective layers which adjoins the catalyst layer. The further the protective layers are from the catalyst layer, the larger the average particle diameters of the oxide particles of the protective layers are.
    Type: Application
    Filed: October 20, 2010
    Publication date: April 21, 2011
    Applicant: DENSO CORPORATION
    Inventors: Takeshi YOSHII, Yasufumi Suzuki, Hirokatsu Imagawa