Patents by Inventor Takuya Ishigaki
Takuya Ishigaki 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).
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Patent number: 12113467Abstract: A power conversion system includes a power conversion device supplying electric power to a motor and a power supply device supplying electric power to the power conversion device. The power conversion device includes a reverse converter that converts the electric power, a control circuit that controls the reverse converter, and a current detector that detects current flowing through the reverse converter. The power supply device includes a storage device that stores electric power in accordance with a voltage, a step-up/down power supply circuit that changes the voltage of the storage device based on a voltage command, and a voltage command computing circuit that computes the energy stored in the storage device and output it as the voltage command to the step-up/down power supply circuit. When the characteristics of the motor are restricted, the voltage command computing circuit temporarily changes the voltage command to improve the motor characteristics.Type: GrantFiled: October 22, 2020Date of Patent: October 8, 2024Assignee: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Yusuke Uei, Takuya Ishigaki, Hideto Takada, Yutaka Matsumoto, Masaki Sugiura
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Patent number: 11998992Abstract: A surface coated cutting tool comprises a tool body. A TiAlCN layer having an average layer thickness of 2.0 to 20.0 ?m and represented by (Ti(1-x)Alx)(CyN(1-y)) is provided on the surface of the tool body and has an average content ratio xavg of Al and an average content ratio yavg of C that satisfy 0.60?xavg?0.95 and 0.00?yavg?0.05, an area ratio occupied by crystal grains having an NaCl-type face-centered cubic structure that satisfies 90 area % or more, and crystal grains satisfying 0.01 ?m<d?0.20 ?m in 10 to 40 area %. An average maximum length in a direction parallel to the surface of the tool body in each region in which the crystal grains having d of 0.01 ?m<d?0.20 ?m are adjacent and connected to each other in the upper layer side region is 5.0 ?m or less.Type: GrantFiled: September 27, 2019Date of Patent: June 4, 2024Assignee: MITSUBISHI MATERIALS CORPORATIONInventors: Takuya Ishigaki, Kousuke Yanagisawa, Hiroki Nakamura, Hisashi Honma
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Publication number: 20230109216Abstract: Provided is a surface-coated cutting tool including a complex carbonitride layer on the tool body, wherein a ratio of crystal grains having a NaCl type face-centered cubic structure is 80 area % or more, xavg and yavg satisfy 0.60?xavg?0.90 and 0.000?yavg?0.050, respectively, a composition of the Ti—Al complex carbonitride layer being represented by (Ti1-xAlx)(CyN1-y), the xavg being an average of x that is an Al content in a total content of Al and Ti, and the yavg being an average of y that is a C content in a total content of C and N, the crystal grains having the NaCl type face-centered cubic structure include crystal grains in which the x repeatedly increases and decreases, the crystal grains include 10 to 40 area % of crystal grains G1 having an average distance of 40 to 160 nm and crystal grains Gs having an average distance of 1 to 7 nm.Type: ApplicationFiled: February 3, 2021Publication date: April 6, 2023Applicant: MITSUBISHI MATERIALS CORPORATIONInventors: Hiroki NAKAMURA, Takuya ISHIGAKI, Kousuke YANAGISAWA, Hisashi HONMA
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Publication number: 20230029493Abstract: A power conversion system 200 includes a power conversion device 2 configured to supply electric power to a motor 3 and a power supply device 1 configured to supply electric power to the power conversion device 2. The power conversion device 2 includes a reverse converter 7 configured to convert the electric power, a control circuit 8 configured to control the reverse converter 7, and a current detector configured to detect a current flowing through the reverse converter 7. The power supply device 1 includes a storage device 6 configured to store electric power in accordance with a voltage, a step-up/down power supply circuit 5 configured to change the voltage of the storage device 6 based on a voltage command, and a voltage command computing circuit 15 configured to compute the energy stored in the storage device 6 and output it as the voltage command to the step-up/down power supply circuit 5.Type: ApplicationFiled: October 22, 2020Publication date: February 2, 2023Inventors: Yusuke UEI, Takuya ISHIGAKI, Hideto TAKADA, Yutaka MATSUMOTO, Masaki SUGIURA
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Patent number: 11424685Abstract: A resonance type power supply device includes: a power supply main circuit having a transformer, a resonance element connected on a primary side of the transformer, and a plurality of switching elements connected to the resonance element; and a power supply control circuit switching the plurality of switching elements in the power supply main circuit with a predetermined switching frequency, in which the power supply control circuit includes: a voltage controller outputting a current command value from a reference voltage, an output voltage of the power supply main circuit, and a voltage control gain; a current controller calculating a reference current, a current flowing on a secondary side of the transformer, and a current control gain; a gain calculator outputting the voltage control gain and the current control gain; and a control signal generator controlling the plurality of switching elements based on the switching frequency outputted by the current controller, and the gain calculator outputs the voltagType: GrantFiled: June 27, 2019Date of Patent: August 23, 2022Assignee: Hitachi Industrial Equipment Systems Co., Ltd.Inventors: Yusuke Uei, Takuya Ishigaki, Tetsuo Yanada
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Publication number: 20220111446Abstract: A surface-coated cutting tool includes a tool body and a hard coating layer, where one TiAlCN layer ? (1) containing 70 area % or more of a wurtzite type hexagonal structure on a tool surface side (S) and one TiAlCN layer ? (2) containing 70 area % or more of a NaCl type face-centered cubic structure on the tool body side (B), when a composition of the TiAlCN layer ? (1) is represented by (Ti(1-x?)Alx?)(Cy?N(1-y?)) satisfying 0.70?x??0.95 and 0.000?y??0.010, when a composition of the TiAlCN layer ? (2) is represented by (Ti(1-x?)Alx?)(Cy?N(1-y?)) satisfying 0.65?x??0.95 and 0.000?y??0.010, and when average layer thicknesses of the TiAlCN layer ? (1) and the TiAlCN layer ? (2) are defined as L? and L? satisfying 0.5 ?m?L??10.0 ?m and 1.0 ?m?L??20.0 ?m.Type: ApplicationFiled: December 26, 2019Publication date: April 14, 2022Applicant: MITSUBISHI MATERIALS CORPORATIONInventors: Takuya ISHIGAKI, Kousuke YANAGISAWA, Hiroki NAKAMURA, Hisashi HONMA
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Publication number: 20210402486Abstract: A surface coated cutting tool comprises a tool body. A TiAlCN layer having an average layer thickness of 2.0 to 20.0 ?m and represented by (Ti(1-x)Alx)(CyN(1-y)) is provided on the surface of the tool body and has an average content ratio xavg of Al and an average content ratio yavg of C that satisfy 0.60?xavg?0.95 and 0.00?yavg?0.05, an area ratio occupied by crystal grains having an NaCl-type face-centered cubic structure that satisfies 90 area % or more, and crystal grains satisfying 0.01 ?m<d?0.20 ?m in 10 to 40 area %. An average maximum length in a direction parallel to the surface of the tool body in each region in which the crystal grains having d of 0.01 ?m<d?0.20 ?m are adjacent and connected to each other in the upper layer side region is 5.0 ?m or less.Type: ApplicationFiled: September 27, 2019Publication date: December 30, 2021Applicant: MITSUBISHI MATERIALS CORPORATIONInventors: Takuya ISHIGAKI, Kousuke YANAGISAWA, Hiroki NAKAMURA, Hisashi HONMA
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Publication number: 20210273568Abstract: A resonance type power supply device includes: a power supply main circuit having a transformer, a resonance element connected on a primary side of the transformer, and a plurality of switching elements connected to the resonance element; and a power supply control circuit switching the plurality of switching elements in the power supply main circuit with a predetermined switching frequency, in which the power supply control circuit includes: a voltage controller outputting a current command value from a reference voltage, an output voltage of the power supply main circuit, and a voltage control gain; a current controller calculating a reference current, a current flowing on a secondary side of the transformer, and a current control gain; a gain calculator outputting the voltage control gain and the current control gain; and a control signal generator controlling the plurality of switching elements based on the switching frequency outputted by the current controller, and the gain calculator outputs the voltagType: ApplicationFiled: June 27, 2019Publication date: September 2, 2021Inventors: Yusuke UEI, Takuya ISHIGAKI, Tetsuo YANADA
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Patent number: 11040402Abstract: A surface-coated cutting tool including at least a TiAlCN layer, in which the layer is expressed by a composition formula: (Ti1-XAlX)(CYN1-Y), an average content ratio X of Al and an average content ratio Y of C (here, X and Y are atomic ratios) satisfy 0.60?X?0.95 and 0?Y?0.005, respectively, an average content ratio Z of Cl in the total amount of atoms configuring the TiAlCN phase (here, Z is an atomic ratio) satisfies 0.0001?Z?0.004, plane spacings d(111) and d(200) are respectively calculated from X-ray diffraction spectra of (111) plane and (200) plane of crystal grains having a NaCl type face-centered cubic structure in the TiAlCN layer measured by using an X-ray diffraction device, and an absolute value ?A=|A(111)?A(200)| defined as A(111)=31/2d(111) and A(200)=2d(200) satisfies 0.007 ???A?0.05.Type: GrantFiled: January 17, 2018Date of Patent: June 22, 2021Assignee: MITSUBISHI MATERIALS CORPORATIONInventors: Takuya Ishigaki, Sho Tatsuoka, Kenichi Sato, Kousuke Yanagisawa, Shin Nishida
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Patent number: 10541549Abstract: An object of the present invention is to provide a charging apparatus having high efficiency of charging a battery by inputting an alternating current voltage. A charging apparatus that charges a direct current battery includes a step-down converter unit to which a direct current voltage from a power supply is input and that converts the direct current voltage, and when a voltage of the direct current battery is between a predetermined first voltage smaller than a charge completion voltage of the direct current battery and the charge completion voltage, a variable voltage that increases from the first voltage to the charge completion voltage in accordance with charging of the direct current battery is input to the step-down converter unit.Type: GrantFiled: April 27, 2016Date of Patent: January 21, 2020Assignee: Hitachi Automotive Systems, Ltd.Inventors: Fumihiro Sato, Takae Shimada, Takuya Ishigaki, Takayuki Ouchi, Hiroyuki Shoji, Naoya Takahashi, Eigo Kishimoto
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Publication number: 20190358711Abstract: A surface-coated cutting tool including at least a TiAlCN layer, in which the layer is expressed by a composition formula: (Ti1-XAlX)(CYN1-Y), an average content ratio X of Al and an average content ratio Y of C (here, X and Y are atomic ratios) satisfy 0.60?X?0.95 and 0?Y?0.005, respectively, an average content ratio Z of Cl in the total amount of atoms configuring the TiAlCN phase (here, Z is an atomic ratio) satisfies 0.0001?Z?0.004, plane spacings d(111) and d(200) are respectively calculated from X-ray diffraction spectra of (111) plane and (200) plane of crystal grains having a NaCl type face-centered cubic structure in the TiAlCN layer measured by using an X-ray diffraction device, and an absolute value ?A=|A(111)?A(200)| defined as A(111)=31/2d(111) and A(200)=2d(200) satisfies 0.007 ???A?0.05.Type: ApplicationFiled: January 17, 2018Publication date: November 28, 2019Applicant: MITSUBISHI MATERIALS CORPORATIONInventors: Takuya ISHIGAKI, Sho TATSUOKA, Kenichi SATO, Kousuke YANAGISAWA, Shin NISHIDA
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Publication number: 20190273440Abstract: Provided is a power converter for converting a DC input voltage to a DC output voltage and outputting the DC output voltage to a load, including: a discharge resistor which discharges electric charges accumulated in the load, a discharge switch which switches an electric conduction state of the discharge resistor; and a discharge controller which controls the discharge switch so that the output voltage becomes a predetermined target voltage, wherein the discharge controller controls the discharge switch to cut off electric conduction of the discharge resistor when the output voltage is lower than a predetermined threshold voltage that is higher than the target voltage, and wherein the discharge controller corrects the threshold voltage in response to a temperature change of the load.Type: ApplicationFiled: May 11, 2017Publication date: September 5, 2019Inventors: Daisuke IKARASHI, Takuya ISHIGAKI, Tatsuro NAMBU, Michihiro ASANUMA
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Publication number: 20180166903Abstract: An object of the present invention is to provide a charging apparatus having high efficiency of charging a battery by inputting an alternating current voltage. A charging apparatus that charges a direct current battery includes a step-down converter unit to which a direct current voltage from a power supply is input and that converts the direct current voltage, and when a voltage of the direct current battery is between a predetermined first voltage smaller than a charge completion voltage of the direct current battery and the charge completion voltage, a variable voltage that increases from the first voltage to the charge completion voltage in accordance with charging of the direct current battery is input to the step-down converter unit.Type: ApplicationFiled: April 27, 2016Publication date: June 14, 2018Inventors: Fumihiro SATO, Takae SHIMADA, Takuya ISHIGAKI, Takayuki OUCHI, Hiroyuki SHOJI, Naoya TAKAHASHI, Eigo KISHIMOTO
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Patent number: 9887638Abstract: If an input voltage of a DC/DC converter is lower than a first voltage value that is set in advance, a converter controller maintains an output voltage of the DC/DC converter within a first voltage range that is set in advance by changing an operation frequency of switching of the DC/DC converter in compliance with the input voltage as a first voltage maintaining control. If the input voltage is higher than a second voltage value that is higher than the first voltage value, the converter controller maintains the output voltage within a second voltage range that is higher than the first voltage range by changing the operation frequency in compliance with the input voltage as a second voltage maintaining control.Type: GrantFiled: February 24, 2016Date of Patent: February 6, 2018Assignee: Hitachi, Ltd.Inventors: Yasuaki Norimatsu, Akihiko Kanouda, Yuuichi Mabuchi, Tadahiko Chida, Takuya Ishigaki, Takae Shimada
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Patent number: 9806622Abstract: Reduction in size and weight of transformer for grid tie applications is demanded and can be achieved by applying SST to the transformer. However, SST application to PCS for sunlight requires the following: handle a wide variation range of the voltage of solar power generation; reduce switching losses of power devices, DC/DC converter and inverter, in the power circuit to implement high frequency for SST application; increase voltage to the grid voltage; and reduce the dimensions of the high current path prior to step-up. Thus, LLC resonant converter configuration is applied with an inverter placed in the output, and series connected configuration is applied to the inverter. The LLC resonant converter is subject to constant frequency regulation with large output, step-up control with low output, and step-down control with the upper limit voltage according to MPPT voltage from sunlight, in order to achieve drive loss reduction and voltage range handling.Type: GrantFiled: May 19, 2016Date of Patent: October 31, 2017Assignee: Hitachi, Ltd.Inventors: Yasuaki Norimatsu, Akihiko Kanouda, Yuuichi Mabuchi, Tadahiko Chida, Takuya Ishigaki, Takae Shimada
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Patent number: 9750125Abstract: Size and weight reduction of a transformer for system interconnection is needed. Applying an SST to the transformer can reduce the size and weight. However, it is also necessary to flexibly handle a wide range of voltages to match a high-voltage system or motor, reduce switching loss of a power device used in a power circuit such as a DC/DC converter and an inverter in association with frequency increase caused by application of the SST, and achieve size reduction of a cooling structure. Further, it is necessary to boost a voltage to a system voltage and reduce the size and weight of a large current path before the voltage boosting. Thus, an LLC resonant converter structure is applied, and a multiple-connection structure is employed in each of which a converter is arranged for an input or an inverter is arranged for an output. This enables handling of various voltage ranges by various combinations of the numbers of multiple connections of the inputs and the outputs.Type: GrantFiled: May 19, 2016Date of Patent: August 29, 2017Assignee: Hitachi, Ltd.Inventors: Yasuaki Norimatsu, Akihiko Kanouda, Yuuichi Mabuchi, Takuya Ishigaki, Takae Shimada
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Publication number: 20160352230Abstract: Size and weight reduction of a transformer for system interconnection is needed. Applying an SST to the transformer can reduce the size and weight. However, it is also necessary to flexibly handle a wide range of voltages to match a high-voltage system or motor, reduce switching loss of a power device used in a power circuit such as a DC/DC converter and an inverter in association with frequency increase caused by application of the SST, and achieve size reduction of a cooling structure. Further, it is necessary to boost a voltage to a system voltage and reduce the size and weight of a large current path before the voltage boosting. Thus, an LLC resonant converter structure is applied, and a multiple-connection structure is employed in each of which a converter is arranged for an input or an inverter is arranged for an output. This enables handling of various voltage ranges by various combinations of the numbers of multiple connections of the inputs and the outputs.Type: ApplicationFiled: May 19, 2016Publication date: December 1, 2016Inventors: Yasuaki NORIMATSU, Akihiko KANOUDA, Yuuichi MABUCHI, Takuya ISHIGAKI, Takae SHIMADA
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Publication number: 20160352229Abstract: Reduction in size and weight of transformer for grid tie applications is demanded and can be achieved by applying SST to the transformer. However, SST application to PCS for sunlight requires the following: handle a wide variation range of the voltage of solar power generation; reduce switching losses of power devices, DC/DC converter and inverter, in the power circuit to implement high frequency for SST application; increase voltage to the grid voltage; and reduce the dimensions of the high current path prior to step-up. Thus, LLC resonant converter configuration is applied with an inverter placed in the output, and series connected configuration is applied to the inverter. The LLC resonant converter is subject to constant frequency regulation with large output, step-up control with low output, and step-down control with the upper limit voltage according to MPPT voltage from sunlight, in order to achieve drive loss reduction and voltage range handling.Type: ApplicationFiled: May 19, 2016Publication date: December 1, 2016Inventors: Yasuaki NORIMATSU, Akihiko KANOUDA, Yuuichi MABUCHI, Tadahiko CHIDA, Takuya ISHIGAKI, Takae SHIMADA
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Publication number: 20160254758Abstract: If an input voltage of a DC/DC converter is lower than a first voltage value that is set in advance, a converter controller maintains an output voltage of the DC/DC converter within a first voltage range that is set in advance by changing an operation frequency of switching of the DC/DC converter in compliance with the input voltage as a first voltage maintaining control. If the input voltage is higher than a second voltage value that is higher than the first voltage value, the converter controller maintains the output voltage within a second voltage range that is higher than the first voltage range by changing the operation frequency in compliance with the input voltage as a second voltage maintaining control.Type: ApplicationFiled: February 24, 2016Publication date: September 1, 2016Inventors: Yasuaki NORIMATSU, Akihiko KANOUDA, Yuuichi MABUCHI, Tadahiko CHIDA, Takuya ISHIGAKI, Takae SHIMADA
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Patent number: 8120345Abstract: A semiconductor device for control applied to a constant-voltage power supply device includes a digital-analog converter circuit which outputs a reference voltage corresponding to a value of a first register with taking an output voltage of a reference voltage source as a criterial reference voltage, and generates a control signal for driving a power semiconductor device based on an output voltage of an error amplifier which differentially amplifies a feedback voltage obtained by resistive-dividing on an output voltage of the constant-voltage power supply device and the reference voltage. An analog-digital converter circuit which converts the feedback voltage to a digital value with taking the output voltage of the constant-voltage power supply device as a reference voltage is provided, and based on the output, a value of a first register is corrected so as to offset an effect of an error in voltage dividing ratio of a voltage dividing resistor circuit.Type: GrantFiled: February 19, 2009Date of Patent: February 21, 2012Assignee: Renesas Electronics CorporationInventors: Noboru Akiyama, Takayuki Hashimoto, Takashi Hirao, Koji Tateno, Takuya Ishigaki