Patents by Inventor Hiroshi Katada
Hiroshi Katada 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: 6766874Abstract: A system for driving a hybrid vehicle comprising an engine; a motor/generator coupled to the engine; a battery connected to the motor/generator through an electric power converter; and a controller for controlling the engine and the motor/generator corresponding to driving condition of the vehicle, wherein the controller has a plurality of operating modes for controlling the engine and the motor/generator corresponding to an accelerator opening degree for operating the engine and a charge ratio of the battery, and the controller selects an engine running electric generating mode that the engine is operated as a driving source of the vehicle and the motor/generator and electric power generated by the motor/generator is recovered to the battery when the charge ratio is low; an acceleration mode that the engine and the motor/generator are operated as the driving source of the vehicle when the charge ratio of the battery is high, and the accelerator opening degree or a rate of change of the accelerator opening deType: GrantFiled: September 29, 1999Date of Patent: July 27, 2004Assignee: Hitachi, Ltd.Inventors: Shotaro Naito, Hiroshi Katada
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Patent number: 6752226Abstract: A system for driving a hybrid vehicle having an engine, a motor/generator, a battery and a controller for the engine and the motor/generator. The controller has a plurality of operating modes. In an engine running electric generating mode, the engine is operated as a driving source of the vehicle and the motor/generator and electric power generated by the motor/generator is recovered to the battery when the charge ratio is low. In an acceleration mode, the engine and the motor/generator are operated as the driving source of the vehicle when the charge ratio of the battery is high, and the accelerator opening degree or a rate of change of the accelerator opening degree is large. In an engine running mode only the engine is operate as the driving source of the vehicle when the charge ratio of the battery is high and the accelerator opening degree is small.Type: GrantFiled: April 2, 2003Date of Patent: June 22, 2004Assignee: Hitachi, Ltd.Inventors: Shotaro Naito, Hiroshi Katada
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Publication number: 20030183430Abstract: A system for driving a hybrid vehicle comprising an engine; a motor/generator coupled to the engine; a battery connected to the motor/generator through an electric power converter; and a controller for controlling the engine and the motor/generator corresponding to driving condition of the vehicle, wherein the controller has a plurality of operating modes for controlling the engine and the motor/generator corresponding to an accelerator opening degree for operating the engine and a charge ratio of the battery, and the controller selects an engine running electric generating mode that the engine is operated as a driving source of the vehicle and the motor/generator and electric power generated by the motor/generator is recovered to the battery when the charge ratio is low; an acceleration mode that the engine and the motor/generator are operated as the driving source of the vehicle when the charge ratio of the battery is high, and the accelerator opening degree or a rate of change of the accelerator opening deType: ApplicationFiled: April 2, 2003Publication date: October 2, 2003Applicant: Hitachi, Ltd.Inventors: Shotaro Naito, Hiroshi Katada
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Publication number: 20020007975Abstract: A system for driving a hybrid vehicle comprising an engine; a motor/generator coupled to the engine; a battery connected to the motor/generator through an electric power converter; and a controller for controlling the engine and the motor/generator corresponding to driving condition of the vehicle, wherein the controller has a plurality of operating modes for controlling the engine and the motor/generator corresponding to an accelerator opening degree for operating the engine and a charge ratio of the battery, and the controller selects an engine running electric generating mode that the engine is operated as a driving source of the vehicle and the motor/generator and electric power generated by the motor/generator is recovered to the battery when the charge ratio is low; an acceleration mode that the engine and the motor/generator are operated as the driving source of the vehicle when the charge ratio of the battery is high, and the accelerator opening degree or a rate of change of the accelerator opening deType: ApplicationFiled: September 29, 1999Publication date: January 24, 2002Inventors: SHOTARO NAITO, HIROSHI KATADA
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Patent number: 6329781Abstract: An apparatus for executing field weakening control comprises a means for computing a start rotational speed of field weakening control based on a ratio of a battery voltage used in a normal operation to a detected battery voltage in execution of only field weakening control without generating a torque, and an interpolation means for carrying out linear interpolation on at least two values selectively fetched from a plurality of current tables in accordance with a battery voltage to find a field weakening current. The apparatus provided by the present invention is further characterized in that, in addition to correction of a start rotational speed of the field weakening control, a field weakening current is corrected in accordance with a ratio of a rated battery voltage used in a normal operation to a detected battery voltage.Type: GrantFiled: February 8, 2000Date of Patent: December 11, 2001Assignee: Hitachi, Ltd.Inventors: Hirokazu Matsui, Hiroshi Katada, Takefumi Sawada
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Patent number: 6236172Abstract: A method and apparatus for driving an electric vehicle having a synchronous traction motor. A peak value of induced electromotive force of the synchronous motor at a maximum allowable rotating speed is set to a value which is lower than an allowable voltage of the smoothing capacitor of the inverter and lower than a maximum allowable voltage of the power switching elements composing the inverter. The synchronous motor is thus constructed so that a peak value V0max of the maximum induced electromotive force at the maximum allowable rotating speed N2 of the synchronous motor satisfies a relation of V0max≦VCmax where VCmax is an allowable voltage of the smoothing capacitor.Type: GrantFiled: June 29, 1999Date of Patent: May 22, 2001Assignee: Hitachi, Ltd.Inventors: Sanshiro Obara, Hiroshi Katada, Suetaro Shibukawa, Nobunori Matsudaira, Shotaro Naito
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Patent number: 6020696Abstract: An inverter main circuit has a DC link capacitor for driving a motor with a power of a battery. An inverter relay is arranged to feed a power of the battery to the inverter main circuit. An auxiliary relay is arranged to feed a power of the battery to the inverter main circuit through a resistor. A main key switch connects the battery to the inverter main circuit through the inverter and auxiliary relays when assuming ON, causing the motor to serve as a generator to charge the DC link capacitor when assuming OFF. When, upon turning the main key switch ON, a speed sensor senses that the rotation speed of the motor is within a predetermined range, a control unit turns the auxiliary relay ON, then the inverter relay ON after shorting armature coils of the motor with the aid of the inverter main circuit and then stops the shorting of the armature coils with the aid of the inverter main circuit.Type: GrantFiled: December 11, 1997Date of Patent: February 1, 2000Assignees: Nissan Motor Co., Ltd., Hitachi, Ltd.Inventors: Yasuo Matsunaga, Kazuya Takahashi, Hiroshi Katada, Eiichi Ohtsu
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Patent number: 5990657Abstract: An inverter system providing both an improvement in the voltage utilization factor and a reduction in the switching loss uses a two-phase switching method. In the inverter system, an .alpha.-axis voltage command value; v.sub..alpha.r and a .beta.-axis voltage command value v.sub..beta.r are input to a stop phase selection means. Six sections are judged based on the values v.sub..alpha.r and v.sub..beta.r to select phases for which it is allowable to stop pulse width modulation control in a two-phase switching method. Then, a phase having the largest absolute value of current is selected among the phases for which it is allowable to stop pulse width modulation control using a U-phase current i.sub.u and a V-phase current i.sub.v. This information is a control mode S. Based on these, two-phase switching calculations are performed by a dead-time compensation calculation means and a pulse width modulation generating means. By doing so, the switching loss can be reduced.Type: GrantFiled: February 28, 1997Date of Patent: November 23, 1999Assignee: Hitachi, Ltd.Inventors: Ryoso Masaki, Yuusuke Takamoto, Satoru Kaneko, Fumio Tajima, Hiroshi Katada
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Patent number: 5914582Abstract: A permanent magnet synchronous motor controller includes an inverter for supplying an alternating current power converted from a direct current power to a three-phase permanent magnet synchronous motor, having a pair of switching elements for each of said three phases of the motor; a smoothing capacitor for smoothing the direct current power connected to the inverter in parallel; and a control unit for controlling the motor by ON-OFF controlling each of the switching elements of the inverter, which further including a short circuit transition processing portion for changing control to 3-phase short circuit after performing precursory ON-OFF control of each of the switching elements so as to avoid occurrence of over current at an initial period of performing the 3-phase short circuit while the motor is being rotated.Type: GrantFiled: January 23, 1998Date of Patent: June 22, 1999Assignee: Hitachi, Ltd.Inventors: Yuusuke Takamoto, Ryoso Masaki, Hiroshi Katada, Sanshiro Obara
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Patent number: 5877601Abstract: In an electric vehicle having a synchronous motor as the driving source, a control system and a control method for the electric vehicle can prevent over current in the main circuit or over charging of the battery at the re-closing of an opened inverter relay and is always capable of operating the power-train system in a better condition. A control method for an electric vehicle having an inverter for supplying a direct current electric power from a battery to the synchronous motor, a smoothing capacitor, connected to the inverter in parallel for smoothing the direct current electric power, an inverter control circuit and an inverter relay for connecting and disconnecting the inverter and the smoothing capacitor to and from the battery. The inverter is controlled so as to prevent current from flowing into or flowing out of the inverter until the re-closing operation of the inverter relay is completed when the opened inverter relay is re-closed.Type: GrantFiled: April 25, 1997Date of Patent: March 2, 1999Assignee: Hitachi, Ltd.Inventors: Sanshiro Obara, Hiroshi Katada, Nobunori Matsudaira, Eiichi Ohtsu, Ryoso Masaki
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Patent number: 5677611Abstract: A control apparatus for an electric vehicle has an inverter for feeding currents to a three-phase AC motor corresponding to applied PWM signals, three current sensors, each of the sensors detecting a current of a respective phase in the three-phase AC motor, a revolution speed detector for detecting the speed of the three-phase AC motor, a motor control unit for controlling the three-phase AC motor which includes a current demand generating unit, a current control unit for performing feedback control based on the current demands and currents detected by the current sensors, and a PWM signal generating unit.Type: GrantFiled: July 1, 1996Date of Patent: October 14, 1997Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.Inventors: Shigeyuki Yoshihara, Hiroshi Katada
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Patent number: 4715353Abstract: An ultrasonic wave type fuel atomizing apparatus for an internal combustion engine provided in an intake passage of the internal combustion engine and atomizing the fuel injected from a fuel injection pump by the ultrasonic wave vibration includes an ultrasonic wave vibrator, an oscillation circuit for generating ultrasonic waves for driving the ultrasonic wave vibrator, and a high voltage generating coil for boosting the output of the oscillation circuit and for applying the driving output to the ultrasonic wave vibrator, and furthermore, a feedback circuit is included to detect a current flowing through the high voltage generating coil and to control an oscillation frequency of the oscillation circuit thereby to make the driving frequency follow the resonance point of the ultrasonic wave vibrator.Type: GrantFiled: December 19, 1986Date of Patent: December 29, 1987Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.Inventors: Hiroshi Koike, Hiroshi Katada, Hiroshi Yoneda
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Patent number: 4627399Abstract: In an engine load detecting apparatus and ignition control apparatus for an internal combustion engine, in accordance with the pulse signals from a reference position detector for detecting a plurality of reference positions of a crankshaft of the engine an interval average rotation speed for each of the intervals between the generation of the pulse signals is calculated and the interval average rotation speeds are utilized in such a manner that a speed pulsation value is obtained from the difference between the maximum and minimum ones thereof and an engine speed is obtained from the average value thereof thereby determining an engine load or ignition timing in accordance with the speed pulsation value and the engine speed.Type: GrantFiled: February 8, 1985Date of Patent: December 9, 1986Assignee: Hitachi, Ltd.Inventors: Tatsuya Yoshida, Hiroshi Katada
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Patent number: 4615318Abstract: An ignition apparatus for an internal combustion engine includes means for generating signals indicating when the crankshaft and camshaft of the engine have respectively reached predetermined angular positions, a command circuit for initiating and terminating ignition operation in response to these position signals, and means for establishing a first operating condition, following each camshaft position pulse, in which the ignition operation is enabled and a second operating condition, following a subsequent crankshaft position pulse, in which ignition operation is inhibited, to thereby eliminate redundant ignition operation and the attendant power loss and heat generation. The apparatus also includes a timer circuit which act to enable resetting to the second operating condition by the crankshaft position pulses only during a fixed time interval following each cam shaft position pulse, in order to ensure stable operation when operating at very low engine speeds.Type: GrantFiled: September 30, 1985Date of Patent: October 7, 1986Assignees: Hitachi, Ltd, Honda Giken Kogyo Kabushiki KaishaInventors: Kosuke Imoto, Hiroshi Katada
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Patent number: 4503823Abstract: An ignition timing control circuit for internal combustion engine comprising a pulse generator which provides a pair of pulses in synchronization with the crank shaft rotation, a pair of polygonal wave generators for providing two types of polygonal waves, one having a constant amplitude, the other having a peak level which varies depending on the engine speed, and a comparator which detects the point of time at which the two waves have the same level and provides an ignition signal at this point, whereby the timing of ignition can be varied automatically, based on the engine speed.Type: GrantFiled: September 15, 1982Date of Patent: March 12, 1985Assignee: Hitachi, Ltd.Inventors: Suetaro Shibukawa, Hiroshi Katada
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Patent number: 4292942Abstract: An ignition system for an internal combustion engine. The ignition system comprises a pulser for generating positive and negative output pulses responsive to the rotation of the engine, a DC power source and an ignition coil having a primary coil connected across the DC power source via a controllable current switching element. The system further comprises a control circuit for controlling the switching element which includes triangular wave generators for generating different triangular wave signals in response to the positive and negative output pulses of the pulser, respectively, a first comparator for comparing a first output signal of one triangular wave generator with a signal which is formed by multiplying a second output signal of the other triangular wave generator by a constant and adding it with a fixed voltage, and a second comparator for comparing the second output signal with a signal which is formed by multiplying the first output signal by a constant and adding it with a fixed voltage.Type: GrantFiled: January 4, 1980Date of Patent: October 6, 1981Assignee: Hitachi, Ltd.Inventors: Hiroshi Katada, Yoshito Kyogoku
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Patent number: 4292943Abstract: A contactless ignition system for use with an internal combustion engine has at least one pulser adapted to detect predetermined maximum and minimum advance angular positions of ignition timing. A first triangular wave form having a first rising gradient and a second triangular wave form having a second rising gradient are formed based on the output of the pulser. When a voltage representative of sum of the first triangular wave form and a reference voltage of a fixed level and the second triangular wave form coincide with each other, an advanced ignition signal of ignition timing is produced, whereby substantially constant advance angles are maintained within low speed range and high speed range of the engine and an advance angle at intermediate speeds of the engine is so controlled as to be proportional to the number of rotations of the engine.Type: GrantFiled: February 26, 1979Date of Patent: October 6, 1981Assignee: Hitachi, Ltd.Inventors: Yoshito Kyogoku, Hiroshi Katada
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Patent number: 4284046Abstract: A contactless ignition system for the internal combustion engine comprises a first integrator for generating a triangular wave voltage V.sub.1 which rises at the minimum advance angle position and is held constant at the maximum advance angle position, a second integrator for generating a triangular wave voltage V.sub.2 which rises at the maximum advance angle position, a first comparator for generating an output signal in response to the coincidence between the first and second triangular wave voltages V.sub.1 and V.sub.2, a third integrator for generating a triangular wave voltage V.sub.3 which rises in response to an output signal generated from the first comparator, and a second comparator for generating an output signal in response to the coincidence between the first and third triangular wave voltages V.sub.1 and V.sub.3. An ignition signal is generated by the output of the second comparator. The change rate of the triangular wave voltage V.sub.Type: GrantFiled: January 17, 1980Date of Patent: August 18, 1981Assignee: Hitachi, Ltd.Inventors: Hideyuki Hashimoto, Yoshito Kyogoku, Hiroshi Katada