Patents by Inventor Masakazu Niwa
Masakazu Niwa 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: 10069444Abstract: A motor control apparatus includes a PWM rectifier which converts AC power on a three-phase AC input power supply side into DC power or which converts DC power on a DC output side into AC power, a smoothing capacitor which is connected to a DC link on the DC output side of the PWM rectifier, a DC voltage detection unit which detects a DC voltage of the smoothing capacitor, an LCL filter which is connected to the AC input power supply side of the PWM rectifier, a power disconnection unit which is connected to an AC power supply side of the LCL filter, and a control unit which applies, when power is disconnected by the power disconnection unit, electric current to the LCL filter by controlling the PWM rectifier, and lowers the DC voltage to a desired value by discharging energy stored in the smoothing capacitor.Type: GrantFiled: October 1, 2015Date of Patent: September 4, 2018Assignee: FANUC CORPORATIONInventor: Masakazu Niwa
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Patent number: 9973116Abstract: A power supply converter controller in an injection molding machine continuously operates a power supply converter in a continuous operation interval, operates the power supply converter in a step-up interval to increase a voltage of an electric storage unit up to a step-up voltage, and intermittently operates the power supply converter in an intermittent operation interval.Type: GrantFiled: March 18, 2015Date of Patent: May 15, 2018Assignee: FANUC CORPORATIONInventors: Junpei Maruyama, Masakazu Niwa
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Patent number: 9923477Abstract: A PWM rectifier includes a main circuit unit carrying out AC-DC power conversion by PWM-control, a PWM control unit PWM-controlling the main circuit unit, a DC voltage detection unit detecting a DC voltage across a smoothing capacitor connected to the DC-side of the main circuit unit, a DC voltage storage unit storing respective DC voltages at the start and end times of an initial boost period during which the smoothing capacitor having been charged to an AC voltage peak value is further charged to a higher voltage, an input power calculation unit calculating input power flowing in from the AC-side based on an AC voltage and current, an integral power calculation unit calculating integral power from the input power over the initial boost period, and a capacitance calculation unit calculating the capacitance of the smoothing capacitor based on the respective DC voltages and the integral power.Type: GrantFiled: December 21, 2016Date of Patent: March 20, 2018Inventor: Masakazu Niwa
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Patent number: 9669665Abstract: A pneumatic tire has carcass layers mounted between a pair of bead parts, the carcass layers being wound from the inner side of the tire to the outer side thereof about a bead core of each bead part. Protective layers including organic fiber cords are positioned in sidewall parts on the outer side of the carcass layers. The upper end parts of the protective layers are positioned along the carcass layers from outer end locations of the belt layers, between a location 20 mm toward the inner side in the tire width direction and a location 15 mm toward the outer side in the tire width direction. The lower end parts of the protective layers are positioned between main body portions of the carcass layers and the bead filler.Type: GrantFiled: September 3, 2013Date of Patent: June 6, 2017Assignee: The Yokohama Rubber Co., LTD.Inventor: Masakazu Niwa
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Publication number: 20170099012Abstract: A PWM rectifier includes a main circuit unit carrying out AC-DC power conversion by PWM-control, a PWM control unit PWM-controlling the main circuit unit, a DC voltage detection unit detecting a DC voltage across a smoothing capacitor connected to the DC-side of the main circuit unit, a DC voltage storage unit storing respective DC voltages at the start and end times of an initial boost period during which the smoothing capacitor having been charged to an AC voltage peak value is further charged to a higher voltage, an input power calculation unit calculating input power flowing in from the AC-side based on an AC voltage and current, an integral power calculation unit calculating integral power from the input power over the initial boost period, and a capacitance calculation unit calculating the capacitance of the smoothing capacitor based on the respective DC voltages and the integral power.Type: ApplicationFiled: December 21, 2016Publication date: April 6, 2017Inventor: Masakazu NIWA
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Patent number: 9602039Abstract: A PWM rectifier includes a main circuit unit which performs a power conversion on the basis of a PWM control signal, a DC voltage loop control unit which generates a current command, a current command restriction unit which sets, when an absolute value of the current command exceeds a limit value, the limit value as a final current command, and otherwise sets the current command as the final current command, a DC voltage loop saturation determination unit which determines a saturation state when the final current command is set to the limit value and otherwise determines as a non-saturation state, a DC voltage command calculation unit which changes the DC voltage command into a value obtained by adding an offset to a minimum or maximum value of the DC voltage value, and a PWM control signal generation unit which generates the PWM control signal from the final current command.Type: GrantFiled: August 10, 2015Date of Patent: March 21, 2017Assignee: Fanuc CorporationInventors: Masakazu Niwa, Kenta Yamamoto
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Publication number: 20160099664Abstract: A motor control apparatus includes a PWM rectifier which converts AC power on a three-phase AC input power supply side into DC power or which converts DC power on a DC output side into AC power, a smoothing capacitor which is connected to a DC link on the DC output side of the PWM rectifier, a DC voltage detection unit which detects a DC voltage of the smoothing capacitor, an LCL filter which is connected to the AC input power supply side of the PWM rectifier, a power disconnection unit which is connected to an AC power supply side of the LCL filter, and a control unit which applies, when power is disconnected by the power disconnection unit, electric current to the LCL filter by controlling the PWM rectifier, and lowers the DC voltage to a desired value by discharging energy stored in the smoothing capacitor.Type: ApplicationFiled: October 1, 2015Publication date: April 7, 2016Inventor: Masakazu NIWA
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Publication number: 20160072403Abstract: A PWM rectifier includes a main circuit unit carrying out AC-DC power conversion by PWM-control, a PWM control unit PWM-controlling the main circuit unit, a DC voltage detection unit detecting a DC voltage across a smoothing capacitor connected to the DC-side of the main circuit unit, a DC voltage storage unit storing respective DC voltages at the start and end times of an initial boost period during which the smoothing capacitor having been charged to an AC voltage peak value is further charged to a higher voltage, an input power calculation unit calculating input power flowing in from the AC-side based on an AC voltage and current, an integral power calculation unit calculating integral power from the input power over the initial boost period, and a capacitance calculation unit calculating the capacitance of the smoothing capacitor based on the respective DC voltages and the integral power.Type: ApplicationFiled: September 9, 2015Publication date: March 10, 2016Inventor: Masakazu NIWA
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Publication number: 20160049895Abstract: A PWM rectifier includes a main circuit unit which performs a power conversion on the basis of a PWM control signal, a DC voltage loop control unit which generates a current command, a current command restriction unit which sets, when an absolute value of the current command exceeds a limit value, the limit value as a final current command, and otherwise sets the current command as the final current command, a DC voltage loop saturation determination unit which determines a saturation state when the final current command is set to the limit value and otherwise determines as a non-saturation state, a DC voltage command calculation unit which changes the DC voltage command into a value obtained by adding an offset to a minimum or maximum value of the DC voltage value, and a PWM control signal generation unit which generates the PWM control signal from the final current command.Type: ApplicationFiled: August 10, 2015Publication date: February 18, 2016Inventors: Masakazu Niwa, Kenta Yamamoto
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Publication number: 20150343847Abstract: A pneumatic having a designated rotational direction, comprises: a tread portion, side wall portions, and bead portions. At least four main grooves extend in a tire circumferential direction. A center land portion is located on a tire equator line. The center land portion has a continuous rib structure in the tire circumferential direction. First inclined grooves are provided from a position near the tire equator line in the center land portion extending to an outside in the tire width direction at an inclination to a direction opposite to the rotational direction and reaching at least as far as a ground contact edge. Second inclined grooves are provided extending from the intermediate land portions to the outside in the tire width direction at an inclination to the direction opposite to the rotational direction and reaching at least as far as the ground contact edge.Type: ApplicationFiled: December 4, 2013Publication date: December 3, 2015Applicant: THE YOKOHAMA RUBBER CO., LTD.Inventor: Masakazu Niwa
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Patent number: 9166514Abstract: A motor control apparatus includes a rectifier for rectifying AC power to output DC power; an inverter for performing power interconversion of DC power of a DC link and AC power being driving power or regenerative power of a motor by being connected to the DC link being a DC output side of the rectifier; and at least two resistance discharge units each for performing resistance discharge of DC power of the DC link, the resistance discharge units each being connected to the DC link, in which each resistance discharge unit starts a resistance discharge operation for performing resistance discharge of DC power of the DC link at a DC voltage value in the DC link exceeding a first threshold value and stops the resistance discharge operation at a DC voltage value in the DC link smaller than a second threshold value below the first threshold value.Type: GrantFiled: September 9, 2013Date of Patent: October 20, 2015Assignee: FANUC CORPORATIONInventors: Masakazu Niwa, Kenta Yamamoto
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Publication number: 20150283864Abstract: A pneumatic tire has carcass layers mounted between a pair of bead parts, the carcass layers being wound from the inner side of the tire to the outer side thereof about a bead core of each bead part. Protective layers including organic fiber cords are positioned in sidewall parts on the outer side of the carcass layers. The upper end parts of the protective layers are positioned along the carcass layers from outer end locations of the belt layers, between a location 20 mm toward the inner side in the tire width direction and a location 15 mm toward the outer side in the tire width direction. The lower end parts of the protective layers are positioned between main body portions of the carcass layers and the bead filler.Type: ApplicationFiled: September 3, 2013Publication date: October 8, 2015Inventor: Masakazu Niwa
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Publication number: 20150270795Abstract: A power supply converter controller in an injection molding machine continuously operates a power supply converter in a continuous operation interval, operates the power supply converter in a step-up interval to increase a voltage of an electric storage unit up to a step-up voltage, and intermittently operates the power supply converter in an intermittent operation interval.Type: ApplicationFiled: March 18, 2015Publication date: September 24, 2015Inventors: Junpei MARUYAMA, Masakazu NIWA
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Patent number: 9118270Abstract: A motor control device includes a rectifier, an inverter connected to the rectifier via the DC link, a power failure detecting unit detecting power failure, a voltage detecting unit detecting a DC voltage at the DC link, an electric storage unit storing DC power, a charging unit that can make charging by boosting to a voltage higher than the DC voltage, a discharging unit discharging DC power, a resistance discharge device that performs resistance discharging of DC power at the DC link when the DC voltage after power failure is equal to or higher than a predetermined start level and that does not perform resistance discharging when the DC voltage is equal to or lower than a predetermined stop level, and a discharging operation determining unit operating the discharging unit when the DC voltage at the DC link after power failure is equal to or lower than a predetermined threshold.Type: GrantFiled: January 28, 2014Date of Patent: August 25, 2015Assignee: Fanuc CorporationInventors: Masakazu Niwa, Kenta Yamamoto
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Patent number: 9054620Abstract: A motor driving device includes a rectifier, an inverter connected to a DC link on a DC side of the rectifier, a power failure detecting unit for detecting a power failure on the alternating side of the rectifier, an electric storage device connected to the DC link, a charging unit that possesses a voltage boosting function of charging the electric storage device by direct current power at the DC link, a discharging unit that causes direct current power stored in the electric storage device to be discharged to the DC link, and a control unit that causes the charging unit to operate when the power failure detecting unit does not detect a power failure, or before start of motor drive, and causes the discharging unit and the inverter to operate when the power failure detecting unit detects a power failure.Type: GrantFiled: July 16, 2013Date of Patent: June 9, 2015Assignee: FANUC CORPORATIONInventors: Masakazu Niwa, Koujirou Sakai
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Publication number: 20150059941Abstract: A pneumatic tire having a carcass layer mounted between a pair of bead portions includes belts layers disposed on an outer circumferential side of the carcass layer at a tread portion, with at least one circumferential groove is disposed in the tread portion so as to continue in the tire circumferential direction in a region on one side of the tire center line. A distance La from the tire center line to a center position of the outermost circumferential groove has a relationship of 0.50×L?La?0.80×L with respect to a tread half-width L from the tire center line to the outer edge position of the tread portion.Type: ApplicationFiled: September 4, 2014Publication date: March 5, 2015Applicant: The Yokohama Rubber Co., LTD.Inventor: Masakazu Niwa
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Publication number: 20140210389Abstract: A motor control device includes a rectifier, an inverter connected to the rectifier via the DC link, a power failure detecting unit detecting power failure, a voltage detecting unit detecting a DC voltage at the DC link, an electric storage unit storing DC power, a charging unit that can make charging by boosting to a voltage higher than the DC voltage, a discharging unit discharging DC power, a resistance discharge device that performs resistance discharging of DC power at the DC link when the DC voltage after power failure is equal to or higher than a predetermined start level and that does not perform resistance discharging when the DC voltage is equal to or lower than a predetermined stop level, and a discharging operation determining unit operating the discharging unit when the DC voltage at the DC link after power failure is equal to or lower than a predetermined threshold.Type: ApplicationFiled: January 28, 2014Publication date: July 31, 2014Applicant: FANUC CORPORATIONInventors: Masakazu Niwa, Kenta Yamamoto
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Patent number: 8786239Abstract: A motor drive PWM rectifier includes a control section which generates the PWM signal in accordance with either a three-phase modulation scheme or a two-phase modulation scheme in which a PWM voltage command for one phase selected from among three phases each constituting the PWM voltage command in the three-phase modulation scheme is set and held at a level equivalent to a maximum value or minimum value of the PWM carrier and in which a PWM voltage command for the other two phases created by also applying an offset, required to achieve the setting, to the other two phases, a detecting section which detects three-phase AC current and outputs a detected current value, and a selecting section which selects the two-phase modulation scheme when the detected current value is larger than a first threshold value but smaller than a second threshold value, and otherwise selects the three-phase modulation scheme.Type: GrantFiled: December 21, 2012Date of Patent: July 22, 2014Assignee: Fanuc CorporationInventors: Yasusuke Iwashita, Masakazu Niwa, Kenta Yamamoto
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Patent number: D724009Type: GrantFiled: April 12, 2013Date of Patent: March 10, 2015Assignee: The Yokohama Rubber Co., Ltd.Inventor: Masakazu Niwa
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Patent number: D777644Type: GrantFiled: August 26, 2014Date of Patent: January 31, 2017Assignee: THE YOKOHAMA RUBBER CO., LTD.Inventors: Masakazu Niwa, Takumi Morito, Wataru Furutani