Patents by Inventor Yasufumi Ikkai

Yasufumi Ikkai 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: 6356001
    Abstract: The invention relates to a motor comprising a stator core having plural teeth and slots provided among the teeth, a winding applied on the teeth by a single turn, and a rotor incorporating plural permanent magnets, which is rotated and driven by utilizing reluctance torque in addition to magnet torque. By turning thus divided teeth by a single winding, the occupation rate of the winding in the slots can be raised. As a result, a motor of small size and large output can be presented.
    Type: Grant
    Filed: April 6, 2000
    Date of Patent: March 12, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Noriyoshi Nishiyama, Tomokazu Nakamura, Yasufumi Ikkai, Yukio Honda, Hiroshi Murakami, Shinichiro Kawano
  • Patent number: 6340857
    Abstract: A motor includes a rotor with interior permanent magnets and a stator with teeth wound by concentrated windings. Each permanent magnet is split along a plane oriented towards the stator, and an electrically insulating section is set between the spilt magnet pieces. This structure allows each permanent magnet to be electrically split, thereby restraining the production of an eddy current. As a result, heat-production is dampened thereby preventing heat demagnetization of the permanent magnets.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: January 22, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Noriyoshi Nishiyama, Tomokazu Nakamura, Yasufumi Ikkai, Masaki Ogushi, Yasuhiro Kondo
  • Patent number: 6324038
    Abstract: In a motor control apparatus, a current control section (1) controls the motor current by judging whether the current value detected by the current detecting unit (4, 7, 14) is of an overcurrent level exceeding an admissible value (Tmax) or a normal level which is equal to or smaller than the admissible value. When the current value detected by the current detecting unit is of an overcurrent level, the current control section restrains the current value to be supplied to the motor irrespective of the external motor torque or speed command, and when the current value detected by the current detecting unit becomes to be the normal level, the current value to be supplied to the motor is restored to an original non-restraint level.
    Type: Grant
    Filed: February 24, 2000
    Date of Patent: November 27, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Taro Kishibe, Yasufumi Ikkai
  • Publication number: 20010043020
    Abstract: A motor includes a rotor with interior permanent magnets and a stator with teeth wound by concentrated windings. The permanent magnet is split along a plane oriented to the stator, and an electrically insulating section is set between the spilt magnet pieces. This structure allows the permanent magnet to be electrically split thereby restraining the production of eddy current. As a result, heat-production is damped thereby preventing heat demagnetization of the permanent magnet.
    Type: Application
    Filed: December 23, 1999
    Publication date: November 22, 2001
    Inventors: NORIYOSHI NISHIYAMA, TOMOKAZU NAKAMURA, YASUFUMI IKKAI, MASAKI OGUSHI, YASUHIRO KONDO
  • Patent number: 6300700
    Abstract: A motor comprises a stator core having plural teeth and slots provided among the teeth, a winding applied on the teeth by a turn, and a rotor incorporating plural permanent magnets. The rotor is rotated and driven by utilizing reluctance torque in addition to magnetic torque. Since the winding is not crossed, the size of the coil end is reduced.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: October 9, 2001
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Noriyoshi Nishiyama, Tomokazu Nakamura, Yasufumi Ikkai, Yukio Honda, Hiroshi Murakami, Shinichiro Kawano
  • Patent number: 6131057
    Abstract: A protecting device of electromobile has control device to control the rotating speed of a motor on the basis of an accelerator signal, a brake signal, and output signals from an encoder sensor, a CS sensor, and a phase current detector, which includes a device for detecting interruption of input of the output signals and outputting detecting signal, a device for stopping supply of electricity to the motor in response to the detecting signal of the detecting device, a device for detecting a value of a phase current of the motor and outputting a detecting signal when the phase current is abnormal, and a device for stopping supply of electricity to the motor in response to the detecting signal of the phase current detecting device
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: October 10, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Tamaki, Yasufumi Ikkai, Yasuhiro Kondo
  • Patent number: 6049153
    Abstract: A motor comprises a stator core having plural teeth and slots provided among the teeth, a winding applied on the teeth by a turn, and a rotor incorporating plural permanent magnets. The rotor is rotated and driven by utilizing reluctance torque in addition to magnetic torque. Since the winding is not crossed, the size of the coil end is reduced.
    Type: Grant
    Filed: February 2, 1998
    Date of Patent: April 11, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Noriyoshi Nishiyama, Tomokazu Nakamura, Yasufumi Ikkai, Yukio Honda, Hiroshi Murakami, Shinichiro Kawano
  • Patent number: 5962999
    Abstract: Torque ripples of a motor having interior permanent magnets can be reduced through the following method and the torque ripple controller using the same method: first, drive the motor having a plurality of phase windings and interior permanent magnets with a basic current supply circuit which outputs a basic current having a predetermined waveform, then store torque ripple waves produced in the running motor or obtained through a numerical analysis into a torque-ripple-wave-memory, next, compensate the torque ripple wave tapped off from the memory according to a prepared torque ripple compensation pattern and transform it to a torque compensation waveform with a torque-compensation-waveform-producing-circuit, further, multiply the torque compensation waveform tapped off from the waveform producing circuit by the basic current with a multiplier to output a torque ripple control current, and, supply the torque ripple control current to the plurality of phase windings shifting a phase by a predetermined electrica
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: October 5, 1999
    Assignee: Matsushita Electric Industrial
    Inventors: Tomokazu Nakamura, Noriyoshi Nishiyama, Yasufumi Ikkai
  • Patent number: 5923728
    Abstract: A motor controller comprises a stator current production unit for producing stator current commands that are command values for the stator current flowing through the stator windings, a drive unit for supplying electric power to the stator windings based on the stator current commands, a stator current detection unit ZU, ZV, and ZW, for detecting the stator currents flowing through the stator windings, and a saturation degree production unit for producing a saturation degree indicating by how much the stator current is not following the stator current command. The stator current production unit produces the stator current commands based on the saturation degree. The saturation degree production unit produces the saturation degree based on the current commands, the stator current signals, and the pole-position signals.
    Type: Grant
    Filed: May 7, 1998
    Date of Patent: July 13, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasufumi Ikkai, Satoshi Tamaki, Masaki Tagome, Mineaki Isoda, Tomokuni Iijima, Kazushige Narazaki
  • Patent number: 5880570
    Abstract: An inverter(3) for driving a motor(4) of an electric automobile(20) produces a three-phase PWM current. When the torque reference is zero, alternatively or when the torque reference is zero and motor speed is no higher than a predetermined value, the inverter(3) is controlled to be cut off so that current from a main power battery(9) is suspended or stopped.
    Type: Grant
    Filed: May 21, 1996
    Date of Patent: March 9, 1999
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Tamaki, Yasuhiro Kondo, Yasufumi Ikkai
  • Patent number: 5757161
    Abstract: A motor control apparatus for detecting motor overspeed in an electric car to prevent destruction of the motor and assure the safety of the vehicle. Torque control is applied when the motor speed is less than a specified rotational velocity. When the motor is detected to be operating at greater than the specified rotational velocity, i.e., when motor overspeed is detected, the motor is controlled to coast or regenerate to lower the motor speed to less than the specified rotational velocity, after which normal control is resumed, thereby preventing collision due to sudden braking and preventing damage to the motor.
    Type: Grant
    Filed: April 21, 1997
    Date of Patent: May 26, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasufumi Ikkai, Satoshi Tamaki
  • Patent number: 5730238
    Abstract: By processing in a control processor 71 signal indicating the amount or degree of pushing-down of the accelerator pedal 2a and signals indicating the non pushing down and full pushing-down of the acceleration pedal 2a, the control unit 7 executes the judgment for determining whether the detected accelerator state is normal or anomalous. In case of judgment of "normal", a usual motor control is executed, whereas in case of judgment to be "anomaly", the system is tentatively designated to be "a state under which the anomaly is being detected". After a specified time lapse, a rejudgement operation is executed, and further when the anomaly is not solved even in this rejudgement operation, the situation is regarded to be a "real anomaly", and an anomaly procedure e.g. to stop current to the motor is executed. When the anomaly state is solved in the rejudgement operation, it is judged to be normal again.
    Type: Grant
    Filed: May 21, 1996
    Date of Patent: March 24, 1998
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Tamaki, Yasufumi Ikkai, Masaki Tagome
  • Patent number: 5592355
    Abstract: When the supply current from a pulse width modulation (PWM) inverter drive circuit supplying current to the motor in an electric-powered motor vehicle is an overcurrent exceeding a particular current level, a monitoring circuit outputs a fail signal to disable the PWM inverter drive circuit and lower the current level. When the current level drops to or below said particular current level, the monitoring circuit re-enables the PWM inverter drive circuit to resume supplying current. If the cumulative output time of the fail signal exceeds a particular period, the PWM inverter drive circuit is determined to not be operating normally, and PWM inverter drive circuit operation is therefore interrupted.
    Type: Grant
    Filed: October 5, 1995
    Date of Patent: January 7, 1997
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasufumi Ikkai, Satoshi Tamaki
  • Patent number: 5504404
    Abstract: In a method and an apparatus for controlling a motor, one type or a plurality of types of weakening current are previously set, a first torque command current determined from a speed deviation between a speed command to the motor and the present speed of the motor is compared with torque currents corresponding the torques, so that a second torque command current and a weakening current are determined and outputted depending on which range of the torque currents corresponding the torques the first torque command current falls upon. Thus, the second torque command current and the weakening current can be determined simply and efficiently.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: April 2, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Tamaki, Yasufumi Ikkai, Yasuhiro Kondo
  • Patent number: 5485375
    Abstract: An electromobile includes a control device which, receiving as inputs a speed command signal outputted from an accelerator sensor and a present motor speed signal outputted from an encoder, calculates a torque command current corresponding to a difference between the inputs, to thereby control the motor in accordance with the torque command current. A protecting device is provided with includes an accelerator switch for switching an outputting state thereof depending on a presence/absence of the control device of the speed command signal. The control device an abnormality detecting device detects an abnormal state in which the torque command current assumes a value to rotate the motor white the output signal of the accelerator switch indicates that the speed command signal is not generated, and an abnormality processing device controls the motor for a safe operation response to an abnormality output from the abnormality detecting device.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: January 16, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Tamaki, Yasufumi Ikkai, Yasuhiro Kondo
  • Patent number: 5444340
    Abstract: In a controlling apparatus of a motor, an address generating device generates digital address signals corresponding to a position of a rotor of the motor on the basis of the Z-phase, A-phase, and B-phase signals outputted from an encoder installed in the motor. A sine wave data for driving the motor is readout based on the digital address signal from a waveform memory device to drive the motor in accordance with the sine wave data by a PWM inverter. An abnormality detecting circuit detects agreement/disagreement of a timing level of an output signal of the waveform memory device which is binarized with using zero as a threshold and shifted a predetermined amount from a leading edge or trailing edge thereof and a level of the CS signal. A motor stopping device stops the motor in response to a disagreement detecting signal of the abnormality detecting circuit.
    Type: Grant
    Filed: September 16, 1994
    Date of Patent: August 22, 1995
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Tamaki, Yasufumi Ikkai, Yasuhiro Kondo
  • Patent number: 5321340
    Abstract: This invention provides a driving method for a three-phase stepping motor used in various types of electrical equipment, which driving method reduces vibration peculiar to a stepping motor and can drive the stepping motor smoothly. Specifically, the driving method comprises alternating two-phase conduction of conducting a current from a first terminal to a second terminal of coils having three terminals of a three-phase stepping motor internally connected by a Y-connection with three-phase conduction of conducting the first terminal to the second terminal and from a third terminal to the second terminal simultaneously, to energize the coils sequentially according to a specified sequence, thereby making the motor rotate in units of 1/2 of the basic step angle with low vibration.
    Type: Grant
    Filed: March 31, 1992
    Date of Patent: June 14, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Tamaki, Yasuhiro Kondo, Yasufumi Ikkai
  • Patent number: 5283510
    Abstract: As a method for energizing a three-phase stepping motor of Y-connection, driving current values are set to be values resembling sine wave input approximation, thus making it possible to effect driving at small vibration. Energizing of the three-phase stepping motor is performed by a two-three phase driving scheme which calls for alternately effecting a two-phase excitation of the coils in the motor and a three-phase excitation of the coils in the motor. The driving current flowing through each of the coils approximates a sine wave having normalized values defined by .+-. 1, .+-. 0.87, .+-. 0.5 and 0.
    Type: Grant
    Filed: May 29, 1992
    Date of Patent: February 1, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Satoshi Tamaki, Yasuhiro Kondo, Yasufumi Ikkai