Patents by Inventor Tetsuo Nakata

Tetsuo Nakata 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: 11824472
    Abstract: A motor drive apparatus includes a motor, a power converter, and a controller that controls the voltage supplied to the motor by the power converter. The power converter converts a voltage of a 400 V-class AC power supply to a voltage with an effective value lower than an effective value of the 400 V-class AC power supply. The power converter converts the voltage by a switching operation of a plurality of switching elements. The motor is configured so that a value of ?×Vx/Ld is greater than Pmax when an effective value voltage Vx=200 V. A d-axis inductance of the motor is Ld. A flux linkage of the motor is ?. A maximum output of the motor in a device where the motor is mounted is Pmax. The controller has a control mode in which an effective value voltage higher than Vx is applied to the motor.
    Type: Grant
    Filed: September 21, 2021
    Date of Patent: November 21, 2023
    Assignee: Daikin Industries, Ltd.
    Inventors: Takayuki Miyajima, Takahiro Yokoyama, Tetsuo Nakata, Junpei Yamamoto
  • Publication number: 20220006408
    Abstract: A motor drive apparatus includes a motor, a power converter, and a controller that controls the voltage supplied to the motor by the power converter. The power converter converts a voltage of a 400 V-class AC power supply to a voltage with an effective value lower than an effective value of the 400 V-class AC power supply. The power converter converts the voltage by a switching operation of a plurality of switching elements. The motor is configured so that a value of ?×Vx/Ld is greater than Pmax when an effective value voltage Vx=200 V. A d-axis inductance of the motor is Ld. A flux linkage of the motor is ?. A maximum output of the motor in a device where the motor is mounted is Pmax. The controller has a control mode in which an effective value voltage higher than Vx is applied to the motor.
    Type: Application
    Filed: September 21, 2021
    Publication date: January 6, 2022
    Inventors: Takayuki MIYAJIMA, Takahiro YOKOYAMA, Tetsuo NAKATA, Junpei YAMAMOTO
  • Patent number: 9366267
    Abstract: An oil-hydraulic unit includes a power module generating heat when energized. The power module is provided on the bottom surface of a recess facing hydraulic oil in a tank. Thus, the power module is cooled by the hydraulic oil in the tank. This reduces the difference in temperature between the power module and the hydraulic oil in the tank. In the oil-hydraulic unit, the temperature sensor detects the temperature of the power module. The oil temperature in the tank is estimated based on the temperature detected by the temperature sensor.
    Type: Grant
    Filed: September 24, 2012
    Date of Patent: June 14, 2016
    Assignee: DAIKIN INDUSTRIES, LTD.
    Inventor: Tetsuo Nakata
  • Publication number: 20140260234
    Abstract: An oil-hydraulic unit includes a power module generating heat when energized. The power module is provided on the bottom surface of a recess facing hydraulic oil in a tank. Thus, the power module is cooled by the hydraulic oil in the tank. This reduces the difference in temperature between the power module and the hydraulic oil in the tank. In the oil-hydraulic unit, the temperature sensor detects the temperature of the power module. The oil temperature in the tank is estimated based on the temperature detected by the temperature sensor.
    Type: Application
    Filed: September 24, 2012
    Publication date: September 18, 2014
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventor: Tetsuo Nakata
  • Patent number: 8805623
    Abstract: A current detector and a voltage detector respectively detect a current value and a voltage value outputted from an engine generator. An operating block determines a weight constant on the basis of the current value and the voltage value, weights the operating time of an engine by using the weight constant, and integrates the weighted operating time to calculate an integral time. A judging block compares the integral time and a reference time, and gives a notification to an indicator when it judges that the integral time exceeds the reference time. Receiving the notification, the indicator makes an external indication. The current detector and the voltage detector can be made of electric circuitry, so that the life of the engine can be predicted at low costs and with high reliability.
    Type: Grant
    Filed: November 1, 2007
    Date of Patent: August 12, 2014
    Assignee: Daikin Industries, Ltd.
    Inventors: Sumikazu Matsuno, Tetsuo Nakata
  • Patent number: 8061028
    Abstract: In a positioning apparatus (40), a fixed scroll (34) is positioned with respect to an assembly body (11) in which a compressor motor (25) has been incorporated. In positioning the fixed scroll (34), electric power is supplied to the compressor motor (25) from an inverter (81) to rotate a crank shaft (20) by the compressor motor (25), thereby shifting a movable scroll (31). In the positioning apparatus (40), the shift of the movable scroll (31) leads to calculation of an appropriate position of the fixed scroll (34). A striking unit (70) applies impact force to the fixed scroll (34) to stir the fixed scroll (34) to the appropriate position.
    Type: Grant
    Filed: January 19, 2006
    Date of Patent: November 22, 2011
    Assignee: Daikin Industries, Ltd.
    Inventors: Takayuki Takahashi, Toshihiro Susa, Kazuhiro Furusho, Atsushi Suhara, Takashi Hirouchi, Tetsuo Nakata
  • Patent number: 7878013
    Abstract: A trailer refrigeration system comprising: an electricity generator (22); an electricity-generator engine (21) for driving the electricity generator (22); a converter (23) for converting ac electric power generated by the electricity generator (22) into dc electric power; an inverter (24, 25, 26) including inverters (24), (25), (26) each for converting dc electric power from the converter (23) into ac electric power; a refrigerant circuit (30) having an electric compressor (31) and a fan (35, 36) including fans (35), (36), the electric compressor (31), the fan (35), and the fan (36) being driven respectively by ac electric power from inverters (24), (25), (26); and a control means (40) for individually controlling the speed of rotation of the electric compressor (31), the fan (35), and the fan (36).
    Type: Grant
    Filed: October 16, 2006
    Date of Patent: February 1, 2011
    Assignee: Dalkin Industries, Ltd.
    Inventors: Sumikazu Matsuno, Tetsuo Nakata, Yuzo Sawada, Fumiaki Yakushiji, Yukio Nishihama, Keisuke Kudou, Yasutoshi Mizutani
  • Patent number: 7684217
    Abstract: Capacitors act as bootstrap capacitors of a high side control circuits. The capacitors are charged in a period in which all of high arm switching devices are non-conductive, so-called in a precharge period. When any of U-phase current, V-phase current and W-phase current is smaller than a negative predetermined value (when an absolute value is larger), it is judged which is the largest value. The low arm switching device is turned on only for a phase corresponding to the current of the largest value and the low arm switching devices of other phases are turned off.
    Type: Grant
    Filed: May 16, 2006
    Date of Patent: March 23, 2010
    Assignee: Daikin industries, Ltd.
    Inventors: Tetsuo Nakata, Yasuto Yanagida
  • Publication number: 20100058785
    Abstract: A current detector and a voltage detector respectively detect a current value and a voltage value outputted from an engine generator. An operating block determines a weight constant on the basis of the current value and the voltage value, weights the operating time of an engine by using the weight constant, and integrates the weighted operating time to calculate an integral time. A judging block compares the integral time and a reference time, and gives a notification to an indicator when it judges that the integral time exceeds the reference time. Receiving the notification, the indicator makes an external indication. The current detector and the voltage detector can be made of electric circuitry, so that the life of the engine can be predicted at low costs and with high reliability.
    Type: Application
    Filed: November 1, 2007
    Publication date: March 11, 2010
    Inventors: Sumikazu Matsuno, Tetsuo Nakata
  • Patent number: 7588422
    Abstract: A pump driving apparatus has a characteristic changing section which receives a set pressure, a set flowing amount, a set horse power, and a DC voltage of the converter section as input, outputs modified values of pressure, flowing amount, and horse power, and supplies the modified values to the horse power command generation section. Therefore, the motor can be driven to suit the change in power voltage so that the motor capacity can be utilized sufficiently.
    Type: Grant
    Filed: November 17, 2003
    Date of Patent: September 15, 2009
    Assignee: Daikin Industries, Ltd.
    Inventors: Yoshiyuki Ochi, Tetsuo Nakata, Yasuto Yanagida
  • Publication number: 20090133419
    Abstract: A trailer refrigeration system comprising: an electricity generator (22); an electricity-generator engine (21) for driving the electricity generator (22); a converter (23) for converting ac electric power generated by the electricity generator (22) into dc electric power; an inverter (24, 25, 26) including inverters (24), (25), (26) each for converting dc electric power from the converter (23) into ac electric power; a refrigerant circuit (30) having an electric compressor (31) and a fan (35, 36) including fans (35), (36), the electric compressor (31), the fan (35), and the fan (36) being driven respectively by ac electric power from inverters (24), (25), (26); and a control means (40) for individually controlling the speed of rotation of the electric compressor (31), the fan (35), and the fan (36).
    Type: Application
    Filed: October 16, 2006
    Publication date: May 28, 2009
    Inventors: Sumikazu Matsuno, Tetsuo Nakata, Yuzo Sawada, Fumiaki Yakushiji, Yukio Nishihama, Keisuke Kudou, Yasutoshi Mizutani
  • Publication number: 20090097986
    Abstract: An oil pressure unit includes an inverter arranged to supply electric power to a motor; a load sensor arranged to detect a load of the oil pressure pump; a rotation sensor arranged to detect a rotation speed of the motor; a current command value calculation part configured to calculate a current command value so that a deviation between a speed command value representing a target rotation speed of the motor and a rotation speed of the motor converges to zero; a correction part configured to correct the current command value based on the load of the oil pressure pump; and a control signal generation part configured to output a control signal to the inverter based on a corrected current command value.
    Type: Application
    Filed: August 27, 2007
    Publication date: April 16, 2009
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Tetsuo Nakata, Junichi Miyagi, Yasuto Yanagida
  • Publication number: 20090027935
    Abstract: Capacitors act as bootstrap capacitors of a high side control circuits. The capacitors are charged in a period in which all of high arm switching devices are non-conductive, so-called in a precharge period. When any of U-phase current, V-phase current and W-phase current is smaller than a negative predetermined value (when an absolute value is larger), it is judged which is the largest value. The low arm switching device is turned on only for a phase corresponding to the current of the largest value and the low arm switching devices of other phases are turned off.
    Type: Application
    Filed: May 16, 2006
    Publication date: January 29, 2009
    Applicant: DAIKIN INDUSTRIES, LTD.
    Inventors: Tetsuo Nakata, Yasuto Yanagida
  • Publication number: 20080152527
    Abstract: In a positioning apparatus (40), a fixed scroll (34) is positioned with respect to an assembly body (11) in which a compressor motor (25) has been incorporated. In positioning the fixed scroll (34), electric power is supplied to the compressor motor (25) from an inverter (81) to rotate a crank shaft (20) by the compressor motor (25), thereby shifting a movable scroll (31). In the positioning apparatus (40), the shift of the movable scroll (31) leads to calculation of an appropriate position of the fixed scroll (34). A striking unit (70) applies impact force to the fixed scroll (34) to stir the fixed scroll (34) to the appropriate position.
    Type: Application
    Filed: January 19, 2006
    Publication date: June 26, 2008
    Inventors: Takayuki Takahashi, Toshihiro Susa, Kazuhiro Furusho, Atsushi Suhara, Takashi Hirouchi, Tetsuo Nakata
  • Patent number: 7207173
    Abstract: An apparatus for warm up control of an autonomous inverter-driven hydraulic unit has a warm up control section and a switch section. The warm up control section performs a predetermined process using a current speed and current pressure as input information and outputs a first switch command. The switch section is controlled by the first switch command so as to control on/off of power supplied to a fan motor. The apparatus causes an oil temperature to quickly rise to a level where a hydraulic unit driven by a hydraulic pump can work in an optimum condition.
    Type: Grant
    Filed: November 17, 2003
    Date of Patent: April 24, 2007
    Assignee: Daikin Industries, Ltd.
    Inventors: Tetsuo Nakata, Yasuto Yanagida, Yoshiyuki Ochi
  • Publication number: 20060153689
    Abstract: A pump driving apparatus has a characteristic changing section which receives a set pressure, a set flowing amount, a set horse power, and a DC voltage of the converter section as input, outputs modified values of pressure, flowing amount, and horse power, and supplies the modified values to the horse power command generation section. Therefore, the motor can be driven to suit the change in power voltage so that the motor capacity can be utilized sufficiently.
    Type: Application
    Filed: November 17, 2003
    Publication date: July 13, 2006
    Applicant: Daikin Industries, Ltd.
    Inventors: Yoshiyuki Ochi, Tetsuo Nakata, Yasuto Yanagida
  • Publication number: 20060150621
    Abstract: An apparatus for warm up control of an autonomous inverter-driven hydraulic unit has a warm up control section and a switch section. The warm up control section performs a predetermined process using a current speed and current pressure as input information and outputs a first switch command. The switch section is controlled by the first switch command so as to control on/off of power supplied to a fan motor. The apparatus causes an oil temperature to quickly rise to a level where a hydraulic unit driven by a hydraulic pump can work in an optimum condition.
    Type: Application
    Filed: November 17, 2003
    Publication date: July 13, 2006
    Applicant: Daikin Industries, Ltd
    Inventors: Tetsuo Nakata, Yasuto Yanagida, Yoshiyuki Ochi
  • Patent number: 6779354
    Abstract: In an oil conditioner comprising: a coolant oil circulation circuit (8) through which a coolant oil of a machine tool (1) is circulated by an oil pump (12); a refrigeration circuit (20) formed by interconnecting, in the order given, a compressor (15), a condenser (16), a pressure reducing mechanism (17), and an evaporator (18) for cooling the coolant oil in the coolant oil circulation circuit (8) by heat exchange with refrigerant; and an inverter (28) for controlling the operating frequency of a motor (14) of the compressor (15), the output from the inverter (28) is switched to a motor (11) of the oil pump (12) during the time the compressor (15) is out of operation so that the amount of coolant oil that the oil pump (12) circulates is made variable, and the amount of coolant oil that the oil pump (12) circulates is reduced when the amount of heat produced in the operation of the machine tool (1) decreases because, for example, the machine tool (1) is stopped, for reducing wasteful consumption of energy by th
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: August 24, 2004
    Assignee: Daikin Industries, Ltd.
    Inventor: Tetsuo Nakata
  • Publication number: 20030079485
    Abstract: In an oil conditioner comprising: a coolant oil circulation circuit (8) through which a coolant oil of a machine tool (1) is circulated by an oil pump (12); a refrigeration circuit (20) formed by interconnecting, in the order given, a compressor (15), a condenser (16), a pressure reducing mechanism (17), and an evaporator (18) for cooling the coolant oil in the coolant oil circulation circuit (8) by heat exchange with refrigerant; and an inverter (28) for controlling the operating frequency of a motor (14) of the compressor (15), the output from the inverter (28) is switched to a motor (11) of the oil pump (12) during the time the compressor (15) is out of operation so that the amount of coolant oil that the oil pump (12) circulates is made variable, and the amount of coolant oil that the oil pump (12) circulates is reduced when the amount of heat produced in the operation of the machine tool (1) decreases because, for example, the machine tool (1) is stopped, for reducing wasteful consumption of energy by th
    Type: Application
    Filed: June 11, 2002
    Publication date: May 1, 2003
    Inventor: Tetsuo Nakata
  • Publication number: 20020188515
    Abstract: The object of the invention is to provide an information processing technology for realizing more efficient physical distribution. Schedule information regarding a form of receiving (for example, “not available for receiving”, “available for receiving”, “forward”, “kept until called for”) a package addressed to the member is received from a terminal of a member and then is registered in a storage device. Further, a delivery form (for example, deliverable or not deliverable for “not available for receiving”) is determined with reference to at least the receiver's schedule stored in the storage device if the receiver is a member. Then, delivery request information for the distributor is generated in accordance with the delivery form if the determined delivery form involves a movement of the package. Accordingly, since a member registers his form of package receiving by himself in advance, he can receive the package in accordance with his schedule.
    Type: Application
    Filed: September 25, 2001
    Publication date: December 12, 2002
    Applicant: Fujitsu Limited
    Inventors: Tetsuo Nakata, Takako Matsuo, Ryohichi Yoshikawa, Atsushi Akagi, Norihiko Akita, Noboru Iida, Takeshi Kudo, Takayuki Shitamori, Takashi Yugami