Patents by Inventor Hiroki Tomizawa

Hiroki Tomizawa 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).

  • Publication number: 20230117373
    Abstract: A control device for a vehicle includes a plurality of control circuits configured to control a control object by starting in response to powering-on of a vehicle and to perform power latch control for continuing to be supplied with electric power in a predetermined period in response to powering-off of the vehicle. Each of the control circuits is configured to perform starting after all of the control circuits have recognized the powering-on of the vehicle in a case where the vehicle is powered on while the power latch control is being performed after the vehicle has been powered off.
    Type: Application
    Filed: October 14, 2022
    Publication date: April 20, 2023
    Applicants: JTEKT CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATION
    Inventors: Yugo NAGASHIMA, Yuji FUJITA, Kazuma HASEGAWA, Yuuta KAJISAWA, Takashi KOUDAI, Masaharu YAMASHITA, Yosuke YAMASHITA, Shintaro TAKAYAMA, Kazuaki IIDA, Hiroyuki KATAYAMA, Hiroki TOMIZAWA, Nobuyori NAKAJIMA
  • Publication number: 20230001983
    Abstract: A steer-by-wire steering system for a vehicle, including: an operating member operable by a driver; a dual-system steering device including two systems each of which includes an electric motor as a drive source, the steering device being configured to steer a wheel; and a controller configured to control a current to be supplied to each of the electric motors of the respective two systems so as to cause the steering device to steer the wheel in accordance with an operation of the operating member, wherein the controller is configured to prohibit the current greater than an upper limit value from being supplied to the electric motors of the respective two systems, and wherein, when the wheel is steered only by only one of the two systems, the controller raises the upper limit value of the current to be supplied to the electric motor of the one of the two systems.
    Type: Application
    Filed: June 30, 2022
    Publication date: January 5, 2023
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, JTEKT Corporation, DENSO CORPORATION
    Inventors: Masaharu YAMASHITA, Masataka OKUDA, Yosuke YAMASHITA, Yuji FUJITA, Yuuta KAJISAWA, Kenichi ABE, Nobuyori NAKAJIMA, Hiroki TOMIZAWA, Takeshi IWANA
  • Publication number: 20220332368
    Abstract: A steer-by-wire steering system for a vehicle, including: an operating member operable by a driver; a steering device including an electric motor and configured to steer a wheel by a force generated by the electric motor; a controller configured to control the steering device, wherein the controller enables the wheel to be steered in accordance with an operation of the operating member while imposing limitation on a supply current to the electric motor, and wherein the limitation imposed on the supply current is made smaller when a running speed of the vehicle is lower than a set speed and a steering motion of the wheel is a motion in a direction to decrease a steering amount than i) when the running speed of the vehicle is not lower than the set speed and ii) when the steering motion of the wheel is a motion in a direction to increase the steering amount.
    Type: Application
    Filed: April 5, 2022
    Publication date: October 20, 2022
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, JTEKT Corporation, DENSO CORPORATION
    Inventors: Masaharu Yamashita, Masataka Okuda, Yosuke Yamashita, Yuji Fujita, Yuuta Kajisawa, Kenichi Abe, Hiroki Tomizawa, Nobuyori Nakajima
  • Publication number: 20220315099
    Abstract: A main power supply having a large capacity and a backup power supply having a small capacity are switchable by a power supply switching determination unit in a system. A motor control device drives a motor by the main power supply or the backup power supply. A drive control unit outputs a drive signal, calculated by feedback control of the current detection value with respect to the current command value, to an inverter circuit. When the power supply switching determination unit switches from the main power supply to the backup power supply, the drive control unit moves from a normal control using the main power supply to a backup control that restricts an electric power consumption and prevents the backup power supply from stopping.
    Type: Application
    Filed: April 1, 2022
    Publication date: October 6, 2022
    Inventors: TAKUYA MAEGAWA, HIROKI TOMIZAWA, HIROYASU OTAKE, YUUTA KAJISAWA, YUJI FUJITA, TOKUAKI HIBINO, YOSUKE YAMASHITA, ATSUSHI SATOU, MASAHARU YAMASHITA
  • Publication number: 20220258794
    Abstract: Control calculation units of a back system in each actuator operate by a collaborative drive mode in which a torque is output to a motor drive unit by using an information transmitted and received mutually by a communication between the systems in common. Cooperative control calculation units in a reaction force actuator and a turning actuator can operate in cooperation with each other based on the information transmitted and received mutually by a communication between actuators. A communication between adjacent systems and a communication between adjacent actuators are restored, when a focus control calculation unit is restored, after the focus control calculation unit is stopped during operation and at least one of the communication between adjacent systems or the communication between adjacent actuators is interrupted.
    Type: Application
    Filed: May 5, 2022
    Publication date: August 18, 2022
    Inventors: AKIRA TAKESAKI, HISASHI KAMEYA, HIROKI TOMIZAWA, MASAHARU YAMASHITA, KENJI SHIBATA, YOSUKE YAMASHITA, SHINTARO TAKAYAMA, TOSHIHIRO TAKAHASHI, YUJI FUJITA, KENICHI ABE, YUGO NAGASHIMA
  • Publication number: 20220250677
    Abstract: A motor drive system includes a first actuator and a second actuator each functioning as a motor configured to output torque. Each of the first actuator and the second actuator includes a plurality of control calculation units and a plurality of motor drive units. The plurality of control calculation units are provided redundantly and each configured to perform a calculation related to a motor drive control. The plurality of motor drive units are provided redundantly and each configured to drive based on a drive signal generated by a corresponding control calculation unit and output the torque.
    Type: Application
    Filed: April 26, 2022
    Publication date: August 11, 2022
    Inventor: HIROKI TOMIZAWA
  • Publication number: 20220255473
    Abstract: A first actuator and a second actuator each have a plurality of control calculation units provided redundantly and a plurality of motor drive units provided redundantly. In the first and the second actuators, the control calculation units of the systems paired with each other transmit and receive information to and from each other by a communication between the actuators. When a failure occurs in any system in either of the two actuators, or when a failure occurs in a communication between actuators in either system, the control calculation unit of each actuator of the system in which the failure occurred stops the motor drive control. Then, the motor drive control is continued by the control calculation unit of the normal system in both actuators.
    Type: Application
    Filed: April 26, 2022
    Publication date: August 11, 2022
    Inventors: HIROKI TOMIZAWA, MASAHARU YAMASHITA, KENJI SHIBATA, YOSUKE YAMASHITA, SHOJI KUBOTA, YUGO NAGASHIMA, YUJI FUJITA, KENICHI ABE
  • Publication number: 20220250676
    Abstract: A motor drive system is provided in a steer-by-wire system in which a steering mechanism and a turning mechanism of a vehicle are mechanically separated. The motor drive system includes a reaction force actuator and a turning actuator. The reaction force actuator functions as a motor configured to output a reaction force torque corresponding to a steering torque of a driver and a road surface reaction force. The turning actuator functions as a motor configured to output a turning torque for turning wheels. Each of the reaction force actuator and the turning actuator includes a plurality of control calculation units provided redundantly and each configured to perform a calculation related to a motor drive control, and a plurality of motor drive units provided redundantly and each configured to drive and output the torque based on a drive signal generated by a corresponding control calculation unit.
    Type: Application
    Filed: April 26, 2022
    Publication date: August 11, 2022
    Inventors: HIROKI TOMIZAWA, HISASHI KAMEYA, SYUJI KURAMITSU, AKIRA TAKESAKI, MASAYA TAKI, MASAHARU YAMASHITA, YOSUKE YAMASHITA, SHINTARO TAKAYAMA, KENJI SHIBATA, TOSHIHIRO TAKAHASHI, YUJI FUJITA, KENICHI ABE, YUGO NAGASHIMA
  • Publication number: 20220255398
    Abstract: A housing is shaped in a bottomed tubular form. A stator is fixed to a stator receiving portion of a tubular portion of the housing at an arbitrary angle position around an axis of the tubular portion. A heat sink is fixed to a heat sink fixing portion of the tubular portion at an arbitrary angle position around the axis of the tubular portion. A control device includes a connector for electrically connecting with an external device and is configured to control energization of the stator. Each of a plurality of externally mounting portions is a part of a bottom portion of the housing and is formed integrally with the housing in one-piece. A plurality of housing positioning holes are formed at the bottom portion of the housing and are arranged at equal intervals along a circle that is concentric with the tubular portion.
    Type: Application
    Filed: April 26, 2022
    Publication date: August 11, 2022
    Inventors: HIROKI TOMIZAWA, ASUKA TANAKA, MASASHI YAMASAKI, TAKAMASA MUTOU, YASUAKI KOYANO, HISASHI YAMAMOTO, YUSUKE SHIKATA
  • Patent number: 11239725
    Abstract: An electric motor includes: a stator; windings wound around the stator; a rotor configured to rotate relative to the stator; a shaft; and a motor case. The shaft is configured to rotate integrally with the rotor, and one end portion of the shaft is coupled to a speed reducing gear device. The motor case includes a tubular portion and a bottom portion, and an opposite side of the tubular portion, which is opposite to the bottom portion, opens. A large diameter portion is formed at an outer periphery of the bottom portion of the motor case and has an outer diameter, which is larger than an outer diameter of a stator fixation location of the motor case, to which the stator is fixed, while the large diameter portion is formed continuously with a contact surface of the bottom portion that is configured to contact a gear housing.
    Type: Grant
    Filed: December 10, 2019
    Date of Patent: February 1, 2022
    Assignee: DENSO CORPORATION
    Inventor: Hiroki Tomizawa
  • Patent number: 10734853
    Abstract: A rotating electric machine is equipped with a consequent-pole type rotor that includes a magnetic pole having a permanent magnet buried therein and a soft magnetic material pole that interposes two magnetic poles. The thickness of the permanent magnet and a circumferential width of the soft magnetic material pole have a relationship that prevents a spread of magnetic flux distribution in the circumferential direction within a gap between the soft magnetic material pole and a stator. As a result, a magnetic flux density difference in the circumferential direction is prevented, which enables a reduction of cogging torque based on an effective reduction of low-frequency space order components that originate from components other than a main component.
    Type: Grant
    Filed: December 10, 2013
    Date of Patent: August 4, 2020
    Assignee: DENSO CORPORATION
    Inventors: Makoto Taniguchi, Hiroki Tomizawa
  • Publication number: 20200195085
    Abstract: An electric motor includes: a stator; windings wound around the stator; a rotor configured to rotate relative to the stator; a shaft; and a motor case. The shaft is configured to rotate integrally with the rotor, and one end portion of the shaft is coupled to a speed reducing gear device. The motor case includes a tubular portion and a bottom portion, and an opposite side of the tubular portion, which is opposite to the bottom portion, opens. A large diameter portion is formed at an outer periphery of the bottom portion of the motor case and has an outer diameter, which is larger than an outer diameter of a stator fixation location of the motor case, to which the stator is fixed, while the large diameter portion is formed continuously with a contact surface of the bottom portion that is configured to contact a gear housing.
    Type: Application
    Filed: December 10, 2019
    Publication date: June 18, 2020
    Inventor: Hiroki TOMIZAWA
  • Patent number: 10427709
    Abstract: A frame is an aluminum die-cast product and includes a frame main body and a frame hole. The frame main body is placed at an inside of an opposite part of a case tubular portion, which is opposite from a case bottom portion. An outer wall of an outer peripheral portion of the frame main body is opposed to an inner wall of the case tubular portion. A receiving space is formed by the frame main body, the case tubular portion and the case bottom portion. The frame hole is formed in a center part of the frame main body. A stator is received in the receiving space. A rotor is rotatable together with a shaft. A seal member is placed between the case tubular portion and a housing of a rack gear and can liquid tightly seal between the case tubular portion and the housing.
    Type: Grant
    Filed: February 1, 2017
    Date of Patent: October 1, 2019
    Assignee: DENSO CORPORATION
    Inventor: Hiroki Tomizawa
  • Patent number: 10312768
    Abstract: An electric motor is provided which is designed to minimize a risk of corrosion or stress corrosion cracking of parts thereof and reduce mechanical vibration or noise. The electric motor includes an output shaft, a bearing which retains the output shaft, a frame, and a biasing member. The biasing member is made of austenite stainless steel and disposed between the bearing and a bottom wall of a bearing housing to elastically press the output shaft in a lengthwise direction thereof for eliminating mechanical noise arising from vibration of a rotor. The frame has a coating formed on an outer surface thereof for avoiding erosion thereof. The coating is not formed at least on a portion of the frame which faces the biasing member in order to induce sacrificial corrosion of the frame, which decelerates the corrosion of the biasing member to eliminate a risk of the stress corrosion cracking thereof.
    Type: Grant
    Filed: May 19, 2017
    Date of Patent: June 4, 2019
    Assignee: DENSO CORPORATION
    Inventors: Hiroki Tomizawa, Koji Isogai
  • Patent number: 10305344
    Abstract: A drive device includes a shaft rotatably supported by a first bearing and a second bearing. The first bearing is disposed in a shaft hole of an output frame end. The second bearing is disposed in a bearing box of an opposite-to-output frame end. An oil seal is fixed in the shaft hole and is closer to an output end than the first bearing is, and is in sliding contact with an outer circumference of the shaft. A biasing member is housed in the bearing box and biases an outer race of the second bearing toward the output end. Accordingly, a deflection amount and a bend amount of the shaft at the location where the oil seal is disposed may be reduced.
    Type: Grant
    Filed: September 30, 2016
    Date of Patent: May 28, 2019
    Assignee: DENSO CORPORATION
    Inventors: Katsuya Fujisaki, Koji Isogai, Hiroki Tomizawa, Makoto Taniguchi, Masahiro Goto
  • Patent number: 10150499
    Abstract: A driving unit includes a stator, a rotor, a shaft, a housing, a protrusion, a small pulley, and a sealing member. The rotor is rotatably disposed relative to the stator. The shaft rotates together with the rotor. The housing houses the stator and the rotor. The protrusion protrudes from an outer surface of the housing toward an outside of the housing. The outer surface is positioned at one side of the housing in an axial direction of the rotor. The small pulley is disposed at an end of the shaft protruding toward the outside of the housing through a hole formed in the protrusion. The small pulley is cylindrical shaped. The sealing member seals a space between an inner surface of the hole of the protrusion and an outer surface of the shaft.
    Type: Grant
    Filed: June 22, 2016
    Date of Patent: December 11, 2018
    Assignee: DENSO CORPORATION
    Inventors: Hiroki Tomizawa, Koji Isogai
  • Patent number: 9893586
    Abstract: A seal member of a driver apparatus contacts a case and a first frame end. The seal member has an opening in which a lead wire is inserted and an inside wall surface of the opening contacts the lead wire. Further, the seal member is made of a stretchable material, and is held in position only by a binding force between the case and the first frame end. The seal member is fixedly held by the first frame end and the case after an insertion of the lead wire in the opening and disposition on the fixing member opposing face. Therefore, an installation of the seal member is performed by an inserting the lead wire into the opening and a positioning the seal member on the case.
    Type: Grant
    Filed: January 30, 2015
    Date of Patent: February 13, 2018
    Assignee: DENSO CORPORATION
    Inventors: HIroki Tomizawa, Makoto Taniguchi, Hiroshi Imai
  • Publication number: 20170338713
    Abstract: An electric motor is provided which is designed to minimize a risk of corrosion or stress corrosion cracking of parts thereof and reduce mechanical vibration or noise. The electric motor includes an output shaft, a bearing which retains the output shaft, a frame, and a biasing member. The biasing member is made of austenite stainless steel and disposed between the bearing and a bottom wall of a bearing housing to elastically press the output shaft in a lengthwise direction thereof for eliminating mechanical noise arising from vibration of a rotor. The frame has a coating formed on an outer surface thereof for avoiding erosion thereof. The coating is not formed at least on a portion of the frame which faces the biasing member in order to induce sacrificial corrosion of the frame, which decelerates the corrosion of the biasing member to eliminate a risk of the stress corrosion cracking thereof.
    Type: Application
    Filed: May 19, 2017
    Publication date: November 23, 2017
    Inventors: Hiroki TOMIZAWA, Koji ISOGAI
  • Publication number: 20170225707
    Abstract: A frame is an aluminum die-cast product and includes a frame main body and a frame hole. The frame main body is placed at an inside of an opposite part of a case tubular portion, which is opposite from a case bottom portion. An outer wall of an outer peripheral portion of the frame main body is opposed to an inner wall of the case tubular portion. A receiving space is formed by the frame main body, the case tubular portion and the case bottom portion. The frame hole is formed in a center part of the frame main body. A stator is received in the receiving space. A rotor is rotatable together with a shaft. A seal member is placed between the case tubular portion and a housing of a rack gear and can liquid tightly seal between the case tubular portion and the housing.
    Type: Application
    Filed: February 1, 2017
    Publication date: August 10, 2017
    Inventor: Hiroki Tomizawa
  • Publication number: 20170104383
    Abstract: A drive device includes a shaft rotatably supported by a first bearing and a second bearing. The first bearing is disposed in a shaft hole of an output frame end. The second bearing is disposed in a bearing box of an opposite-to-output frame end. An oil seal is fixed in the shaft hole and is closer to an output end than the first bearing is, and is in sliding contact with an outer circumference of the shaft. A biasing member is housed in the bearing box and biases an outer race of the second bearing toward the output end. Accordingly, a deflection amount and a bend amount of the shaft at the location where the oil seal is disposed may be reduced.
    Type: Application
    Filed: September 30, 2016
    Publication date: April 13, 2017
    Applicants: DENSO CORPORATION, ASMO CO., LTD.
    Inventors: Katsuya FUJISAKI, Koji ISOGAI, Hiroki TOMIZAWA, Makoto TANIGUCHI, Masahiro GOTO