Patents by Inventor Junji Hayakawa

Junji Hayakawa 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: 10815555
    Abstract: A heat-resistant, austenitic cast steel having excellent thermal fatigue properties, comprising by mass 0.3-0.6% of C, 0.5-3% of Si, 0.5-2% of Mn, 15-30% of Cr, 6-30% of Ni, 0.6-5% of Nb, 0.01-0.5% of N, and 0.01-0.5% of S, C/N being 4-7, and the balance being Fe and inevitable impurities; and a ratio A/B of a Cr-carbide-forming index A to a Nb-carbide-forming index B being 0.6-1.7, wherein A and B are expressed by the formula (1) of A=8.5C?Nb+0.05Cr+0.65Ni?5, and the formula (2) of B=7.8Nb.
    Type: Grant
    Filed: October 5, 2015
    Date of Patent: October 27, 2020
    Assignee: HITACHI METALS, LTD.
    Inventors: Hirofumi Kimura, Tomonori Namito, Susumu Katsuragi, Junji Hayakawa
  • Publication number: 20170298489
    Abstract: A heat-resistant, austenitic cast steel having excellent thermal fatigue properties, comprising by mass 0.3-0.6% of C, 0.5-3% of Si, 0.5-2% of Mn, 15-30% of Cr, 6-30% of Ni, 0.6-5% of Nb, 0.01-0.5% of N, and 0.01-0.5% of S, C/N being 4-7, and the balance being Fe and inevitable impurities; and a ratio A/B of a Cr-carbide-forming index A to a Nb-carbide-forming index B being 0.6-1.7, wherein A and B are expressed by the formula (1) of A=8.5C?Nb+0.05Cr+0.65Ni?5, and the formula (2) of B=7.8Nb.
    Type: Application
    Filed: October 5, 2015
    Publication date: October 19, 2017
    Applicant: HITACHI METALS, LTD.
    Inventors: Hirofumi KIMURA, Tomonori NAMITO, Susumu KATSURAGI, Junji HAYAKAWA
  • Patent number: 9046029
    Abstract: A heat-resistant, ferritic cast steel having excellent melt flowability, gas defect resistance, toughness and machinability, which has a composition comprising by mass, C: 0.32-0.45%, Si: 0.85% or less, Mn: 0.15-2%, Ni: 1.5% or less, Cr: 16-23%, Nb: 3.2-4.5%, Nb/C: 9-11.5, N: 0.15% or less, S: (Nb/20?0.1) to 0.2%, W and/or Mo: 3.2% or less in total (W+Mo), the balance being Fe and inevitable impurities, and a structure in which the area ratio of a eutectic (?+NbC) phase of ? ferrite and Nb carbide (NbC) is 60-80%, and the area ratio of manganese chromium sulfide (MnCr)S is 0.2-1.2%, and an exhaust member made thereof.
    Type: Grant
    Filed: October 3, 2011
    Date of Patent: June 2, 2015
    Assignee: HITACHI METALS, LTD.
    Inventors: Masahide Kawabata, Hideo Kuribayashi, Junji Hayakawa
  • Publication number: 20130195713
    Abstract: A heat-resistant, ferritic cast steel having excellent melt flowability, gas defect resistance, toughness and machinability, which has a composition comprising by mass, C: 0.32-0.45%, Si: 0.85% or less, Mn: 0.15-2%, Ni: 1.5% or less, Cr: 16-23%, Nb: 3.2-4.5%, Nb/C: 9-11.5, N: 0.15% or less, S: (Nb/20-0.1) to 0.2%, W and/or Mo: 3.2% or less in total (W+Mo), the balance being Fe and inevitable impurities, and a structure in which the area ratio of a eutectic (?+NbC) phase of ? ferrite and Nb carbide (NbC) is 60-80%, and the area ratio of manganese chromium sulfide (MnCr)S is 0.2-1.2%, and an exhaust member made thereof.
    Type: Application
    Filed: October 3, 2011
    Publication date: August 1, 2013
    Applicant: HITACHI METALS, LTD.
    Inventors: Masahide Kawabata, Hideo Kuribayashi, Junji Hayakawa
  • Patent number: 7795881
    Abstract: A capacitive physical quantity detection device comprising a plurality of capacitive physical quantity sensors, wherein each sensor includes: a detection unit having a movable electrode and a fixed electrode; a C-V conversion circuit having a differential amplifier circuit, wherein a first input terminal of the differential amplifier circuit is coupled with the movable electrode, a second input terminal of the differential amplifier circuit inputs a reference voltage and a self-diagnosis voltage therein during a normal operation and a self-diagnosis operation, respectively, and the C-V conversion circuit outputs an output voltage; and a signal processing circuit that performs a signal processing of the output voltage, wherein the reference voltage in each sensor is substantially the same, the plurality of sensors performs the self-diagnosis operation simultaneously, and the self-diagnosis voltage in one of the sensors is a first self-diagnosis voltage that is different in magnitude from the self-diagnosis vol
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: September 14, 2010
    Assignee: DENSO CORPORATION
    Inventors: Masashi Masuda, Junji Hayakawa
  • Patent number: 7642913
    Abstract: A sensor apparatus includes a sensor circuit and a nonlinear signal processing circuit. The sensor circuit detects a physical quantity and outputs a detection signal indicative of the detected physical quantity. The signal processing circuit includes a logarithmic converter, an analog-to-digital converter, and an antilogarithmic converter. The logarithmic converter produces a logarithm signal corresponding to a logarithm of the detection signal. The analog-to-digital converter digitalizes the logarithm signal. The antilogarithmic converter produces an antilogarithmic signal corresponding to an antilogarithm of the digitalized logarithm signal.
    Type: Grant
    Filed: November 29, 2007
    Date of Patent: January 5, 2010
    Assignee: DENSO CORPORATION
    Inventor: Junji Hayakawa
  • Patent number: 7640806
    Abstract: A capacitive physical quantity sensor includes a sensor element and a detecting element. The sensor element includes first and second fixed electrodes facing a movable electrode. A first voltage is applied to the first fixed electrode and a second voltage is applied to the second fixed electrode. The detecting circuit includes a capacitance-voltage conversion circuit, in which an operational amplifier, a capacitor and a switch including a P-channel MOS transistor and a N-channel MOS transistor are disposed. The transistors have a back gate potential, which is approximately equal to an average voltage of the first voltage and the second voltage.
    Type: Grant
    Filed: December 21, 2006
    Date of Patent: January 5, 2010
    Assignee: DENSO CORPORATION
    Inventors: Akinobu Umemura, Junji Hayakawa
  • Patent number: 7501885
    Abstract: A filter circuit includes a voltage amplifier, a resistor, a capacitor, and an analog switch connected between the voltage amplifier and the capacitor. When the voltage amplifier is turned on, the analog switch is opened so that the capacitor is disconnected from the voltage amplifier. Thus, an output voltage of the voltage amplifier sharply increases to its steady state value, as soon as the voltage amplifier is turned on. When the output voltage of the voltage amplifier is fully stabilized, the analog switch is closed so that the capacitor is connected to the voltage amplifier. During the period of time when the analog switch is closed, the filter circuit is configured as an imperfect integrator circuit with filter characteristics that depend on a capacitance of the capacitor and a resistance of the resistor.
    Type: Grant
    Filed: March 13, 2007
    Date of Patent: March 10, 2009
    Assignee: DENSO CORPORATION
    Inventors: Norio Kitao, Junji Hayakawa
  • Patent number: 7456731
    Abstract: A substrate forming a sensor element is connected to a non-inverting input terminal of an operational amplifier, and a common voltage is applied thereto from a reference voltage supply circuit to fix them to the same potential. Thus, the impedances of the non-inverting input terminal and of the inverting input terminal of the operational amplifier are matched with respect to the power source. Therefore, noise superposed on a power source line can be greatly decreased by noise-removing characteristics determined by CMRR characteristics of the operational amplifier. As a result, a capacitive-type acceleration sensor exhibits sensor characteristics of frequency noise suppressing effect.
    Type: Grant
    Filed: May 2, 2006
    Date of Patent: November 25, 2008
    Assignee: DENSO CORPORATION
    Inventors: Akinobu Umemura, Junji Hayakawa, Takaaki Kawai
  • Publication number: 20080191714
    Abstract: A capacitive physical quantity detection device comprises: a plurality of capacitive physical quantity sensors, wherein each sensor including: a detection unit having a movable electrode and a fixed electrode; a C-V conversion circuit having a differential amplifier circuit, wherein a first input terminal of the differential amplifier circuit is coupled with the movable electrode, a second input terminal of the differential amplifier circuit inputs a reference voltage and a self-diagnosis voltage therein during a normal operation and a self-diagnosis operation, respectively, and the C-V conversion circuit outputs an output voltage; and a signal processing circuit that performs a signal processing of the output voltage, wherein the reference voltage in each sensor is almost the same, the plurality of sensors performs the self-diagnosis operation simultaneously, the self-diagnosis voltage in one of the sensors is a first self-diagnosis voltage is different from the self-diagnosis voltage in another one of the s
    Type: Application
    Filed: January 17, 2008
    Publication date: August 14, 2008
    Applicant: DENSO CORPORATION
    Inventors: Masashi Masuda, Junji Hayakawa
  • Publication number: 20080136627
    Abstract: A sensor apparatus includes a sensor circuit and a nonlinear signal processing circuit. The sensor circuit detects a physical quantity and outputs a detection signal indicative of the detected physical quantity. The signal processing circuit includes a logarithmic converter, an analog-to-digital converter, and an antilogarithmic converter. The logarithmic converter produces a logarithm signal corresponding to a logarithm of the detection signal. The analog-to-digital converter digitalizes the logarithm signal. The antilogarithmic converter produces an antilogarithmic signal corresponding to an antilogarithm of the digitalized logarithm signal.
    Type: Application
    Filed: November 29, 2007
    Publication date: June 12, 2008
    Applicant: DENSO CORPORATION
    Inventor: Junji Hayakawa
  • Patent number: 7295045
    Abstract: An output signal cutting-off circuit includes a first switching element, a driving circuit and a voltage-drop-signal generating circuit. When a voltage to be monitored becomes lower than a threshold voltage, a voltage-drop-signal is generated and supplied to the driving circuit. The driving circuit turns on the first switching element based on the voltage-drop-signal to thereby cut off an output signal voltage by bringing it to a ground potential. When the voltage-drop-signal disappears, the first switching element is turned off to bring the output signal to a normal state. Preferably, a second switching element for charging a capacitor and a third switching element for discharging the capacitor are used in the driving circuit. In this case, the first switching element is turned on or off based on a voltage of the capacitor.
    Type: Grant
    Filed: December 8, 2005
    Date of Patent: November 13, 2007
    Assignee: DENSO CORPORATION
    Inventors: Takaaki Kawai, Junji Hayakawa
  • Publication number: 20070216474
    Abstract: A filter circuit includes a voltage amplifier, a resistor, a capacitor, and an analog switch connected between the voltage amplifier and the capacitor. When the voltage amplifier is turned on, the analog switch is opened so that the capacitor is disconnected from the voltage amplifier. Thus, an output voltage of the voltage amplifier sharply increases to its steady state value, as soon as the voltage amplifier is turned on. When the output voltage of the voltage amplifier is fully stabilized, the analog switch is closed so that the capacitor is connected to the voltage amplifier. During the period of time when the analog switch is closed, the filter circuit is configured as an imperfect integrator circuit with filter characteristics that depend on a capacitance of the capacitor and a resistance of the resistor.
    Type: Application
    Filed: March 13, 2007
    Publication date: September 20, 2007
    Applicant: DENSO CORPORATION
    Inventors: Norio Kitao, Junji Hayakawa
  • Publication number: 20070159183
    Abstract: A capacitive physical quantity sensor includes a sensor element and a detecting element. The sensor element includes first and second fixed electrodes facing a movable electrode. A first voltage is applied to the first fixed electrode and a second voltage is applied to the second fixed electrode. The detecting circuit includes a capacitance-voltage conversion circuit, in which an operational amplifier, a capacitor and a switch including a P-channel MOS transistor and a N-channel MOS transistor are disposed. The transistors have a back gate potential, which is approximately equal to an average voltage of the first voltage and the second voltage.
    Type: Application
    Filed: December 21, 2006
    Publication date: July 12, 2007
    Applicant: DENSO CORPORATION
    Inventors: Akinobu Umemura, Junji Hayakawa
  • Publication number: 20060250267
    Abstract: A substrate forming a sensor element is connected to a non-inverting input terminal of an operational amplifier, and a common voltage is applied thereto from a reference voltage supply circuit to fix them to the same potential. Thus, the impedances of the non-inverting input terminal and of the inverting input terminal of the operational amplifier are matched with respect to the power source. Therefore, noise superposed on a power source line can be greatly decreased by noise-removing characteristics determined by CMRR characteristics of the operational amplifier. As a result, a capacitive-type acceleration sensor exhibits sensor characteristics of frequency noise suppressing effect.
    Type: Application
    Filed: May 2, 2006
    Publication date: November 9, 2006
    Applicant: DENSO CORPORATION
    Inventors: Akinobu Umemura, Junji Hayakawa, Takaaki Kawai
  • Patent number: 7109727
    Abstract: In a capacitive physical quantity sensor, a C-V converter converts a variation in a capacitance between a movable electrode and a fixed electrode into a voltage to output the converted voltage in a first operating mode. The C-V converter also outputs a constant voltage in a second operating mode. An amplifier amplifies the converted voltage to output a first voltage, and amplifies the constant voltage to output a second voltage. A first sample and hold circuit operates in the first operating mode to sample and hold the first voltage. A second sample and hold circuit operates in the second operating mode to sample and hold the second voltage. A first differential amplifier obtains a difference voltage between the first voltage held by the first sample and hold circuit and the second voltage held by the second sample and hold circuit.
    Type: Grant
    Filed: September 16, 2005
    Date of Patent: September 19, 2006
    Assignee: Denso Corporation
    Inventors: Junji Hayakawa, Norio Kitao, Akinobu Umemura, Hirokazu Ito, Takaaki Kawai
  • Patent number: 7106031
    Abstract: In a power supply apparatus, a switching circuit selectively applies one of an input voltage of a power converting circuit and an output voltage of the power converting circuit to a voltage reducing power supply circuit. When the input voltage is applied to the power converting circuit, the switching circuit selects this input voltage, so that the output voltage of the voltage reducing power supply circuit can quickly rise. Thereafter, when the output voltage of the power converting circuit exceeds this output voltage, the switching circuit selects the output voltage of the power converting circuit. As a result, a difference between the input voltage and the output voltage of the voltage reducing power supply circuit is decreased. Thus, a power loss is lowered and noise produced in the power converting circuit is suppressed.
    Type: Grant
    Filed: February 10, 2005
    Date of Patent: September 12, 2006
    Assignee: Denso Corporation
    Inventors: Junji Hayakawa, Hiroyuki Ban, Jyunichi Nagata
  • Publication number: 20060164129
    Abstract: An output signal cutting-off circuit includes a first switching element, a driving circuit and a voltage-drop-signal generating circuit. When a voltage to be monitored becomes lower than a threshold voltage, a voltage-drop-signal is generated and supplied to the driving circuit. The driving circuit turns on the first switching element based on the voltage-drop-signal to thereby cut off an output signal voltage by bringing it to a ground potential. When the voltage-drop-signal disappears, the first switching element is turned off to bring the output signal to a normal state. Preferably, a second switching element for charging a capacitor and a third switching element for discharging the capacitor are used in the driving circuit. In this case, the first switching element is turned on or off based on a voltage of the capacitor.
    Type: Application
    Filed: December 8, 2005
    Publication date: July 27, 2006
    Applicant: DENSO CORPORATION
    Inventors: Takaaki Kawai, Junji Hayakawa
  • Publication number: 20060061372
    Abstract: In a capacitive physical quantity sensor, a C-V converter converts a variation in a capacitance between a movable electrode and a fixed electrode into a voltage to output the converted voltage in a first operating mode. The C-V converter also outputs a constant voltage in a second operating mode. An amplifier amplifies the converted voltage to output a first voltage, and amplifies the constant voltage to output a second voltage. A first sample and hold circuit operates in the first operating mode to sample and hold the first voltage. A second sample and hold circuit operates in the second operating mode to sample and hold the second voltage. A first differential amplifier obtains a difference voltage between the first voltage held by the first sample and hold circuit and the second voltage held by the second sample and hold circuit.
    Type: Application
    Filed: September 16, 2005
    Publication date: March 23, 2006
    Applicant: DENSO CORPORATION
    Inventors: Junji Hayakawa, Norio Kitao, Akinobu Umemura, Hirokazu Ito, Takaaki Kawai
  • Publication number: 20050206323
    Abstract: In a power supply apparatus, a switching circuit selectively applies one of an input voltage of a power converting circuit and an output voltage of the power converting circuit to a voltage reducing power supply circuit. When the input voltage is applied to the power converting circuit, the switching circuit selects this input voltage, so that the output voltage of the voltage reducing power supply circuit can quickly rise. Thereafter, when the output voltage of the power converting circuit exceeds this output voltage, the switching circuit selects the output voltage of the power converting circuit. As a result, a difference between the input voltage and the output voltage of the voltage reducing power supply circuit is decreased. Thus, a power loss is lowered and noise produced in the power converting circuit is suppressed.
    Type: Application
    Filed: February 10, 2005
    Publication date: September 22, 2005
    Inventors: Junji Hayakawa, Hiroyuki Ban, Jyunichi Nagata