Patents by Inventor Takehiko Kowatari

Takehiko Kowatari 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: 6401690
    Abstract: An electrically-controlled throttle valve apparatus includes a motor, a speed reducing mechanism for reducing rotation speed transmitted from the motor, a throttle valve connected to the speed reducing mechanism, and a force applying device applying force to the throttle valve in the direction of returning the valve to its initial position and adjusting the opening of the throttle valve by driving the motor. Parameters of the motor, the speed reducing mechanism, and the force applying device have values such that the operation time t from the minimum to the maximum throttle valve opening, which is determined by an evaluation equation obtained from equations of throttle valve motion, is less than a prescribed target throttle valve operation time t*. Furthermore, resistance and an induction voltage constant of the motor are determined to satisfy a constraint equation obtained based on Ohm's law.
    Type: Grant
    Filed: July 11, 2000
    Date of Patent: June 11, 2002
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Takehiko Kowatari, Yuzo Kadomukai, Shigeru Tokumoto, Yasuo Saito, Toshifumi Usui, Masaru Ito
  • Patent number: 6386182
    Abstract: A device for controlling the flow of intake air to an engine includes an air flow meter for detecting the flow rate of air, an electronically controlled throttle for opening and closing a throttle valve, and an electric motor that drives the throttle valve via a gear. The air flow meter and electric motor are arranged on opposite respective sides of a plane that include an axis of the throttle valve and that extends in a direction of the flow of intake air in the engine.
    Type: Grant
    Filed: January 19, 2001
    Date of Patent: May 14, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Takehiko Kowatari, Yuzo Kadomukai, Toshihiro Aono, Toshifumi Usui
  • Publication number: 20020045982
    Abstract: An intake air flow rate measurement apparatus for measuring a flow rate of intake air taken in an internal combustion engine, using an electrothermal resistor type air flowmeter, includes a delay/non-linearity correction part to perform correction of an output signal of the electrothermal resistor type air flowmeter for a response delay and a non-linearity of the electrothermal resistor type air flowmeter; a waveform feature value extraction part to extract feature values of a waveform of an output signal which has been sent from said electrothermal resistor type air flowmeter and has been corrected for said response delay and non-linearity by the delay/non-linearity correction part; a back flow calculation part to obtain a back flow ratio based on the extracted waveform feature values; and a flow rate calculation part to obtain a correct flow rate of the intake air based on an output of the delay/non-linearity correction part and an output of the back flow ratio calculation part.
    Type: Application
    Filed: November 2, 2001
    Publication date: April 18, 2002
    Inventors: Toshihiro Aono, Takehiko Kowatari
  • Patent number: 6334083
    Abstract: An intake air flow rate measurement apparatus for measuring a flow rate of intake air taken in an internal combustion engine, using an electrothermal resistor type air flowmeter, includes a delay/non-linearity correction part to perform correction of an output signal of the electrothermal resistor type air flowmeter for a response delay and a non-linearity of the electrothermal resistor type air flowmeter; a waveform feature value extraction part to extract feature values of a waveform of an output signal which has been sent from said electrothermal resistor type air flowmeter and has been corrected for said response delay and non-linearity by the delay/non-linearity correction part; a back flow calculation part to obtain a back flow ratio based on the extracted waveform feature values; and a flow rate calculation part to obtain a correct flow rate of the intake air based on an output of the delay/non-linearity correction part and an output of the back flow ratio calculation part.
    Type: Grant
    Filed: October 12, 1999
    Date of Patent: December 25, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiro Aono, Takehiko Kowatari
  • Publication number: 20010027776
    Abstract: A main passage mounting a throttle valve and an air bypass flow passage for reducing HC emission by promoting atomization of the fuel spray injected from the assembly pipe fuel injector are integrated in a body of an intake air control device arranged upstream of an assembly pipe in one-piece structure to form a unit. Thereby, the intake air control device can be easily manufactured, and easily mounted on and dismounted from the intake air system. An amount of HC emitted at warming-up operation of an internal combustion engine is reduced by efficiently supplying fuel spray injected from an assembly pipe fuel injector at starting and warming-up operations to the internal combustion engine.
    Type: Application
    Filed: March 29, 2001
    Publication date: October 11, 2001
    Inventors: Kiyoshi Amou, Yoshio Okamoto, Yuzo Kadomukai, Takehiko Kowatari, Ayumu Miyajima, Masami Nagano, Takanobu Ichihara, Hiroaki Saeki, Tadashi Someno
  • Publication number: 20010025628
    Abstract: Atomizing air flowing in an atomizing gas passage is merged with fuel spray to promote atomization of the fuel, and carrier air flowing in a carrier gas passage is merged with the fuel spray at a further downstream position so as to surround around the fuel spray. By doing so, the atomized fuel spray is carried to the downstream side so as to prevent the fuel spray from adhering onto the wall surface. Starting-up performance, fuel consumption and exhaust gas cleaning of an internal combustion engine are improved.
    Type: Application
    Filed: March 29, 2001
    Publication date: October 4, 2001
    Inventors: Kiyoshi Amou, Yoshio Okamoto, Takehiko Kowatari, Ayumu Miyajima, Yuzo Kadomukai, Toru Ishikawa, Masami Nagano, Takanobu Ichihara, Hiroaki Saeki, Kenji Watanabe
  • Publication number: 20010017126
    Abstract: There is provided an air flow meter for detecting the flow rate of air, an electronically controlled throttle for opening and closing a throttle valve and a calculating device to which a target engine intake air flow rate, a value detected by the air flow meter, the position of a throttle valve detected by a throttle position sensor, and a value detected by an engine speed sensor are input. The calculating device calculates a time constant of a delay of response of the air flow rate into the engine, and a air flow rate passing through the throttle valve to compensate for the delay of response, and drives the throttle valve such that the flow rate of air passing through the throttle valve agrees with the calculated value.
    Type: Application
    Filed: January 19, 2001
    Publication date: August 30, 2001
    Applicant: Hitachi, Ltd.
    Inventors: Takehiko Kowatari, Yuzo Kadomukai, Toshihiro Aono, Toshifumi Usui
  • Patent number: 6199537
    Abstract: There is provided an air flow meter for detecting the flow rate of air, an electronically controlled throttle for opening and closing a throttle valve and a calculating device to which a target engine intake air flow rate, a value detected by the air flow meter, the position of a throttle valve detected by a throttle position sensor, and a value detected by an engine speed sensor are input. The calculating device calculates a time constant of a delay of response of the air flow rate into the engine, and a air flow rate passing through the throttle valve to compensate for the delay of response, and drives the throttle valve such that the flow rate of air passing through the throttle valve agrees with the calculated value.
    Type: Grant
    Filed: September 17, 1999
    Date of Patent: March 13, 2001
    Assignee: Hitachi, Ltd.
    Inventors: Takehiko Kowatari, Yuzo Kadomukai, Toshihiro Aono, Toshifumi Usui
  • Patent number: 6098594
    Abstract: An electrically-controlled throttle valve apparatus includes a motor, a speed reducing mechanism for reducing the rotation speed that is transmitted from the motor, a throttle valve connected to the speed reducing mechanism, and a force applying arrangement for applying force to the throttle valve in the direction of returning the valve to its initial position and for adjusting the opening of the throttle valve by driving the motor. Specification parameters of the motor, the speed reducing mechanism, and the force applying arrangement have values such that the operation time t from the minimum opening to the maximum opening of the throttle valve, which is determined by an evaluation equation obtained from equations of motion of the throttle valve, is less than a prescribed target operation time t* of the throttle valve. Furthermore, the resistance and the induction voltage constant of the motor are determined so as to satisfy a constraint equation obtained based on Ohm's law.
    Type: Grant
    Filed: October 21, 1998
    Date of Patent: August 8, 2000
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Takehiko Kowatari, Yuzo Kadomukai, Shigeru Tokumoto, Yasuo Saito, Toshifumi Usui, Masaru Ito
  • Patent number: 6089208
    Abstract: When the power source of a motor is turned off, a cam connected to the motor is held at an initial default stopping position by a return spring generating a torque in one direction and a throttle valve connected to a cam via an arm, and a valve gear is held at a corresponding default opening position. When the motor rotates and generates its torque, the arm first closes the throttle valve to a prescribed minimum opening and then opens the throttle valve in the fully open direction.
    Type: Grant
    Filed: September 18, 1998
    Date of Patent: July 18, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Takehiko Kowatari, Shigeru Tokumoto, Kousaku Ohno
  • Patent number: 5952571
    Abstract: In a thermal type flow meter having a temperature compensating bridge circuit, the temperature compensating bridge circuit includes a heating resistor, a temperature compensating resistor and a plurality of resistors each having a fixed resistance. The heating resistor and the temperature compensating resistor are supported by a support member in an air flow passage, and the support member is formed by a material having a small temperature coefficient .DELTA..lambda. of thermal conductivity between -0.06 and 0.06 w/m.multidot.k.sup.2. The absolute value of the output error of the flow meter is reduced as a result of variation of the flow quantity or flow velocity of intake air and the intake air temperature.
    Type: Grant
    Filed: September 22, 1997
    Date of Patent: September 14, 1999
    Assignees: Hitachi, Ltd., Hitachi Car Engineering Co., Ltd.
    Inventors: Nobukatsu Arai, Takehiko Kowatari, Kaoru Uchiyama, Izumi Watanabe, Shinya Igarashi
  • Patent number: 5832403
    Abstract: A digital signal obtained by A/D converting an output of a thermal type air flow meter is supplied along two paths. After a time constant is obtained in one path, inverse-transformation is performed to obtain an error together with an output of the other path. The inverse-transformed signal is linearized on the basis of the characteristic of the thermal type air flow meter, and a direction of flow is determined.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: November 3, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Takehiko Kowatari, Nobukatsu Arai, Kaoru Uchiyama, Chihiro Kobayashi, Shinya Igarashi
  • Patent number: 5750889
    Abstract: An air flow rate measuring apparatus for measuring an intake air amount of an internal combustion engine by use of a thermal air flow meter comprises means inputted with the output of the thermal air flow meter for correcting a response delay of the output and outputting the corrected output, and means inputted with the output of the correcting means for transforming it to a value corresponding to an air flow rate on the basis of the characteristic of the thermal air flow meter stored beforehand.
    Type: Grant
    Filed: February 13, 1996
    Date of Patent: May 12, 1998
    Assignee: Hitachi, Ltd.
    Inventors: Takehiko Kowatari, Nobukatsu Arai, Chihiro Kobayashi