Patents by Inventor Makoto Asai

Makoto Asai 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: 11749675
    Abstract: Between a source electrode (25) of a main device (24) and a current sensing electrode (22) of a current detection device (21), a resistor for detecting current is connected. Dielectric withstand voltage of gate insulator (36) is larger than a product of the resistor and maximal current flowing through the current detection device (21) with reverse bias. A diffusion length of a p-body region (32) of the main device (24) is shorter than that of a p-body (31) of the current detection device (21). A curvature radius at an end portion of the p-body region (32) of the main device (24) is smaller than that of the p-body (31) of the current detection device (21). As a result, at the inverse bias, electric field at the end portion of the p-body region (32) of the main device (24) becomes stronger than that of the p-body region (31) of the current detection device (21). Consequently, avalanche breakdown tends to occur earlier in the main device 24 than the current detection device (21).
    Type: Grant
    Filed: January 7, 2021
    Date of Patent: September 5, 2023
    Assignees: FUJI ELECTRIC CO., LTD., DENSO CORPORATION
    Inventors: Seiji Momota, Hitoshi Abe, Takashi Shiigi, Takeshi Fujii, Koh Yoshikawa, Tetsutaro Imagawa, Masaki Koyama, Makoto Asai
  • Patent number: 11480144
    Abstract: A fuel supply system includes an electronic control unit that outputs a target fuel pressure for controlling a low-pressure pump and an engine status, and a fuel pump controller (FPC) that generates a drive signal for driving the low-pressure pump based on the target fuel pressure. The FPC is configured to obtain an actual fuel pressure, to set a duty ratio and to perform a feedback control for the actual fuel pressure to follow the target fuel pressure, and to set a lower limit guard value based on the engine status. The lower limit guard setter sets a duty ratio of 0% as the lower limit guard value when the engine status indicates a stop of the engine.
    Type: Grant
    Filed: February 27, 2019
    Date of Patent: October 25, 2022
    Assignee: DENSO CORPORATION
    Inventor: Makoto Asai
  • Patent number: 11401594
    Abstract: Provided are a hot-rolled steel sheet for coiled tubing and a method for manufacturing the steel sheet. The steel sheet has a yield strength of 480 MPa or more, a tensile strength of 600 MPa or more, a yield-strength difference (?YS) of 100 MPa or more, where the yield-strength difference is defined as a difference in yield strength between before and after a prestrain-heat treatment performed for simulation of a tube-making process and a stress-relief annealing heat treatment which are currently implemented, and a yield strength of 620 MPa or more after the prestrain-heat treatment.
    Type: Grant
    Filed: January 16, 2019
    Date of Patent: August 2, 2022
    Assignee: JFE Steel Corporation
    Inventors: Hideyuki Kimura, Shuji Kawamura, Ichiro Sugimoto, Makoto Asai, Takeshi Yokota
  • Publication number: 20210134789
    Abstract: Between a source electrode (25) of a main device (24) and a current sensing electrode (22) of a current detection device (21), a resistor for detecting current is connected. Dielectric withstand voltage of gate insulator (36) is larger than a product of the resistor and maximal current flowing through the current detection device (21) with reverse bias. A diffusion length of a p-body region (32) of the main device (24) is shorter than that of a p-body (31) of the current detection device (21). A curvature radius at an end portion of the p-body region (32) of the main device (24) is smaller than that of the p-body (31) of the current detection device (21). As a result, at the inverse bias, electric field at the end portion of the p-body region (32) of the main device (24) becomes stronger than that of the p-body region (31) of the current detection device (21). Consequently, avalanche breakdown tends to occur earlier in the main device 24 than the current detection device (21).
    Type: Application
    Filed: January 7, 2021
    Publication date: May 6, 2021
    Applicants: FUJI ELECTRIC CO., LTD., DENSO CORPORATION
    Inventors: Seiji Momota, Hitoshi Abe, Takashi Shiigi, Takeshi Fujii, Koh Yoshikawa, Tetsutaro Imagawa, Masaki Koyama, Makoto Asai
  • Publication number: 20210054487
    Abstract: Provided are a hot-rolled steel sheet for coiled tubing and a method for manufacturing the steel sheet. The steel sheet has a yield strength of 480 MPa or more, a tensile strength of 600 MPa or more, a yield-strength difference (AYS) of 100 MPa or more, where the yield-strength difference is defined as a difference in yield strength between before and after a prestrain-heat treatment performed for simulation of a tube-making process and a stress-relief annealing heat treatment which are currently implemented, and a yield strength of 620 MPa or more after the prestrain-heat treatment.
    Type: Application
    Filed: January 16, 2019
    Publication date: February 25, 2021
    Applicant: JFE Steel Corporation
    Inventors: Hideyuki Kimura, Shuji Kawamura, Ichiro Sugimoto, Makoto Asai, Takeshi Yokota
  • Patent number: 10916541
    Abstract: Between a source electrode (25) of a main device (24) and a current sensing electrode (22) of a current detection device (21), a resistor for detecting current is connected. Dielectric withstand voltage of gate insulator (36) is larger than a product of the resistor and maximal current flowing through the current detection device (21) with reverse bias. A diffusion length of a p-body region (32) of the main device (24) is shorter than that of a p-body (31) of the current detection device (21). A curvature radius at an end portion of the p-body region (32) of the main device (24) is smaller than that of the p-body (31) of the current detection device (21). As a result, at the inverse bias, electric field at the end portion of the p-body region (32) of the main device (24) becomes stronger than that of the p-body region (31) of the current detection device (21). Consequently, avalanche breakdown tends to occur earlier in the main device 24 than the current detection device (21).
    Type: Grant
    Filed: September 2, 2016
    Date of Patent: February 9, 2021
    Assignees: FUJI ELECTRIC CO., LTD., DENSO CORPORATION
    Inventors: Seiji Momota, Hitoshi Abe, Takashi Shiigi, Takeshi Fujii, Koh Yoshikawa, Tetsutaro Imagawa, Masaki Koyama, Makoto Asai
  • Patent number: 10787986
    Abstract: A fuel pump controller performs a feedback control of an actual fuel pressure of a feed pump to a command fuel pressure which is from an external element. The pump controller changes a gain for the feedback control to a value larger than a minimum value of the gain in response to an acceleration command information which is to accelerate a vehicle by using an internal combustion engine.
    Type: Grant
    Filed: November 20, 2018
    Date of Patent: September 29, 2020
    Assignee: DENSO CORPORATION
    Inventors: Minoru Kobayashi, Makoto Asai
  • Patent number: 10731575
    Abstract: A lower limit setting portion of a fuel pump control system sets a lower limit value depending on an engine operating mode. For example, it sets a duty ratio of 0% as the lower limit value, when the engine operating mode is in a STOP mode in a turned-on condition of an ignition switch. A duty-ratio calculating portion carries out a feedback control in order that an actual fuel pressure comes closer to a target fuel pressure by use of the lower limit value and calculates a duty ratio for driving a fuel pump by the feedback control. An abnormal condition determining portion determines an abnormal condition based on the duty ratio and pump current. The abnormal condition determining portion further determines based on a remaining fuel amount whether the abnormal condition is caused by a disconnection or whether the abnormal condition is caused by an idling operation of the fuel pump due to fuel shortage.
    Type: Grant
    Filed: June 4, 2019
    Date of Patent: August 4, 2020
    Assignee: DENSO CORPORATION
    Inventors: Takuya Sugie, Makoto Asai
  • Patent number: 10605506
    Abstract: A heat pump includes a control device configured to control conduction and shutting-off of electric power to a first compressor heater, and to control whether or not an alarm unit notifies an alarm. The control device causes the alarm unit to notify the alarm when the control device determines that duration of electric conduction to the first compressor heater is a predetermined period or longer. With this, it is possible to provide a heat pump that can control electric conduction to the heater to enable saving of electricity, and that can detect a problem in the controlling of the electric conduction to the heater.
    Type: Grant
    Filed: March 11, 2016
    Date of Patent: March 31, 2020
    Assignee: YANMAR CO., LTD.
    Inventors: Hirotoshi Kihara, Keiji Sugimori, Sadanori Yasuda, Hirotaka Nakamura, Makoto Asai
  • Publication number: 20200095948
    Abstract: A lower limit setting portion of a fuel pump control system sets a lower limit value depending on an engine operating mode. For example, it sets a duty ratio of 0% as the lower limit value, when the engine operating mode is in a STOP mode in a turned-on condition of an ignition switch. A duty-ratio calculating portion carries out a feedback control in order that an actual fuel pressure comes closer to a target fuel pressure by use of the lower limit value and calculates a duty ratio for driving a fuel pump by the feedback control. An abnormal condition determining portion determines an abnormal condition based on the duty ratio and pump current. The abnormal condition determining portion further determines based on a remaining fuel amount whether the abnormal condition is caused by a disconnection or whether the abnormal condition is caused by an idling operation of the fuel pump due to fuel shortage.
    Type: Application
    Filed: June 4, 2019
    Publication date: March 26, 2020
    Inventors: Takuya SUGIE, Makoto ASAI
  • Publication number: 20190271288
    Abstract: A fuel supply system includes an electronic control unit that outputs a target fuel pressure for controlling a low-pressure pump and an engine status, and a fuel pump controller (FPC) that generates a drive signal for driving the low-pressure pump based on the target fuel pressure. The FPC is configured to obtain an actual fuel pressure, to set a duty ratio and to perform a feedback control for the actual fuel pressure to follow the target fuel pressure, and to set a lower limit guard value based on the engine status. The lower limit guard setter sets a duty ratio of 0% as the lower limit guard value when the engine status indicates a stop of the engine.
    Type: Application
    Filed: February 27, 2019
    Publication date: September 5, 2019
    Inventor: Makoto ASAI
  • Publication number: 20190186403
    Abstract: A fuel pump controller performs a feedback control of an actual fuel pressure of a feed pump to a command fuel pressure which is from an external element. The pump controller changes a gain for the feedback control to a value larger than a minimum value of the gain in response to an acceleration command information which is to accelerate a vehicle by using an internal combustion engine.
    Type: Application
    Filed: November 20, 2018
    Publication date: June 20, 2019
    Inventors: Minoru KOBAYASHI, Makoto ASAI
  • Publication number: 20180080694
    Abstract: A heat pump includes a control device configured to control conduction and shutting-off of electric power to a first compressor heater, and to control whether or not an alarm unit notifies an alarm. The control device causes the alarm unit to notify the alarm when the control device determines that duration of electric conduction to the first compressor heater is a predetermined period or longer. With this, it is possible to provide a heat pump that can control electric conduction to the heater to enable saving of electricity, and that can detect a problem in the controlling of the electric conduction to the heater.
    Type: Application
    Filed: March 11, 2016
    Publication date: March 22, 2018
    Applicant: Yanmar Co., Ltd.
    Inventors: Hirotoshi KIHARA, Keiji SUGIMORI, Sadanori YASUDA, Hirotaka NAKAMURA, Makoto ASAI
  • Publication number: 20180058356
    Abstract: In cases where a control device determines that a load is continuously less than a predetermined value for a predetermined period, the control device executes a first control to maintain the engine speed at a first rotation speed or higher, and when the control device determines that the load reached the predetermined value within the predetermined time, the control device executes a second control to maintain the engine speed at a second rotation speed or higher, which is higher than the first rotation speed. This provides a control device for an engine and an engine, which can restrain activation of an oil pressure switch attributed to an oil temperature.
    Type: Application
    Filed: March 11, 2016
    Publication date: March 1, 2018
    Applicant: Yanmar Co., Ltd.
    Inventors: Hirotoshi KIHARA, Hirotaka NAKAMURA, Shiro TANIHARA, Kyoko HASHIMOTO, Makoto ASAI, Takafumi KUBO
  • Publication number: 20160372460
    Abstract: Between a source electrode (25) of a main device (24) and a current sensing electrode (22) of a current detection device (21), a resistor for detecting current is connected. Dielectric withstand voltage of gate insulator (36) is larger than a product of the resistor and maximal current flowing through the current detection device (21) with reverse bias. A diffusion length of a p-body region (32) of the main device (24) is shorter than that of a p-body (31) of the current detection device (21). A curvature radius at an end portion of the p-body region (32) of the main device (24) is smaller than that of the p-body (31) of the current detection device (21). As a result, at the inverse bias, electric field at the end portion of the p-body region (32) of the main device (24) becomes stronger than that of the p-body region (31) of the current detection device (21). Consequently, avalanche breakdown tends to occur earlier in the main device 24 than the current detection device (21).
    Type: Application
    Filed: September 2, 2016
    Publication date: December 22, 2016
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Seiji Momota, Hitoshi Abe, Takashi Shiigi, Takeshi Fujii, Koh Yoshikawa, Tetsutaro Imagawa, Masaki Koyama, Makoto Asai
  • Patent number: 9466711
    Abstract: Between a source electrode (25) of a main device (24) and a current sensing electrode (22) of a current detection device (21), a resistor for detecting current is connected. Dielectric withstand voltage of gate insulator (36) is larger than a product of the resistor and maximal current flowing through the current detection device (21) with reverse bias. A diffusion length of a p-body region (32) of the main device (24) is shorter than that of a p-body (31) of the current detection device (21). A curvature radius at an end portion of the p-body region (32) of the main device (24) is smaller than that of the p-body (31) of the current detection device (21). As a result, at the inverse bias, electric field at the end portion of the p-body region (32) of the main device (24) becomes stronger than that of the p-body region (31) of the current detection device (21). Consequently, avalanche breakdown tends to occur earlier in the main device 24 than the current detection device (21).
    Type: Grant
    Filed: January 28, 2009
    Date of Patent: October 11, 2016
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Seiji Momota, Hitoshi Abe, Takashi Shiigi, Takeshi Fujii, Koh Yoshikawa, Tetsutaro Imagawa, Masaki Koyama, Makoto Asai
  • Publication number: 20160229083
    Abstract: In a method of producing a die for extrusion molding, a treated surface is provided on an inner wall surface of a second through hole. The die includes a raw material supply section having a first through hole that extends from a first face toward a second face. The die includes a molding section having the second through hole that extends from the second face toward the first face. In providing the treated surface, a material for the die is machined to form the material into a die shape and to provide a machining-affected layer on the inner wall surface of the second through hole in the molding section, an oxidized layer is provided by heating the machining-affected layer to oxidize the machining-affected layer so as to convert the machining-affected layer into the oxidized layer, and the oxidized layer is removed.
    Type: Application
    Filed: April 20, 2016
    Publication date: August 11, 2016
    Applicant: IBIDEN CO., LTD.
    Inventors: Makoto ASAI, Shuichi KAWANO
  • Patent number: 9099387
    Abstract: A semiconductor device includes an n-conductive type semiconductor substrate having a main side and a rear side, a p-conductive type layer arranged over the main side of the substrate, a main side n-conductive type region arranged in the p-conductive type layer, a rear side n-conductive type layer arranged over the rear side of the substrate, a first trench which reaches the substrate and penetrates the main side n-conductive type region and the p-conductive type layer, a second trench which reaches an inside of the p-conductive type layer, a second electrode layer, which is embedded in the second trench and connected to the p-conductive type layer. Hereby, the semiconductor device, in which the recovery property of a diode cell can be improved without damaging the property of a MOS transistor cell or an IGBT cell and the surge withstand property does not deteriorate, can be obtained.
    Type: Grant
    Filed: June 28, 2011
    Date of Patent: August 4, 2015
    Assignee: DENSO CORPORATION
    Inventors: Yukio Tsuzuki, Makoto Asai
  • Publication number: 20150014902
    Abstract: A die for extrusion molding includes a first face, a second face, a raw material supply section, a molding section, and a structure. The molding section has a second through hole that extends from the second face toward the first face so as to communicate with a first through hole. The structure is such that a material for the die is machined to form the material into a predetermined shape and to provide a machining-affected layer on an inner wall surface of the second through hole in the molding section, an oxidized layer is provided by heating the machining-affected layer to oxidize the machining-affected layer so as to convert the machining-affected layer into the oxidized layer, the oxidized layer is removed so that a treated surface is provided, and the treated surface is nitrided by ion implantation to provide a nitride layer.
    Type: Application
    Filed: September 29, 2014
    Publication date: January 15, 2015
    Applicant: IBIDEN CO., LTD.
    Inventors: Kiyotaka ANDO, Shuichi KAWANO, Makoto ASAI
  • Publication number: 20150014903
    Abstract: A die for extrusion molding includes a first face, a second face, a raw material supply section, a molding section, and a treated surface. The second face is provided opposite the first face. The molding section has a second through hole that extends from the second face toward the first face so as to communicate with a first through hole. The treated surface is provided on an inner wall surface of the second through hole to have a structure such that a material for the die is machined to form the material into a die shape and to provide a machining-affected layer on the inner wall surface of the second through hole in the molding section, an oxidized layer is provided by heating the machining-affected layer to oxidize the machining-affected layer so as to convert the machining-affected layer into the oxidized layer, and the oxidized layer is removed.
    Type: Application
    Filed: September 29, 2014
    Publication date: January 15, 2015
    Applicant: IBIDEN CO., LTD.
    Inventors: Makoto ASAI, Shuichi KAWANO