Patents by Inventor Hirokazu Watai

Hirokazu Watai 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: 9939038
    Abstract: Swirl chamber units (31) allowing a first liquid chamber (14) and a second liquid chamber (15) to communicate with each other are formed in a partitioning member of a vibration-damping device (10) of the present invention. Each swirl chamber unit (31) includes a first communication hole (32a) opening to the first liquid chamber (14), and a second communication hole (32b) opening to the second liquid chamber (15); a first swirl chamber (33a) communicating with the first liquid chamber (14) via the first communication hole (32a), and a second swirl chamber (33b) communicating with the second liquid chamber (15) via the second communication hole (32b); and a flow regulation passage (34) that allows the first swirl chamber (33a) and the second swirl chamber (33b) to communicate with each other and opens to the swirl chambers (33a, 33b) in circumferential directions of the respective swirl chambers (33a, 33b).
    Type: Grant
    Filed: October 15, 2014
    Date of Patent: April 10, 2018
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Akira Ueki, Shingo Oono, Hirokazu Watai, Masakazu Nagasawa
  • Patent number: 9857776
    Abstract: A rotational signal of a generation source of a control object is detected and, when a rotational speed (frequency) varies, convergence values of filter coefficients of adaptive filters 33, 34 based on a previous control result corresponding to the frequency stored in a control device 11 are retrieved and set to the adaptive filters 33, 34 as initial values. The adaptive filters 33, 34 are updated by using the initial values of filter coefficients and output a control signal y(t) to an ACM (actuator) 3a. LMS arithmetic units 37, 39 read a reference signal calculated from the rotational signal and an acceleration signal (error signal) e(t) detected by a sensor 9 and carry out processing for updating the filter coefficients of the adaptive filters 33, 34. The adaptive filters 33, 34, based on updated filter coefficients, output the control signal y(t) to the ACM 3a.
    Type: Grant
    Filed: March 13, 2012
    Date of Patent: January 2, 2018
    Assignee: BRIDGESTONE CORPORATION
    Inventors: Hirokazu Watai, Kazutomo Murakami
  • Publication number: 20170234397
    Abstract: This disclosure is to provide an anti-vibration device with reduced high frequency vibration. The anti-vibration device (1) according to this disclosure has: elastic bodies (4); and an intermediate plate (5) arranged between the elastic bodies (4) and connected to the elastic bodies (4). The intermediate plate (5) has an acoustic impedance (Z2) larger than the elastic bodies (4), and a perpendicular line (O) of the intermediate plate (5) is arranged between the elastic bodies (4) in a manner inclined with respect to the vibration input direction at an angle (?1).
    Type: Application
    Filed: September 30, 2015
    Publication date: August 17, 2017
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Yuki SATAKE, Hirokazu WATAI, Akira UEKI
  • Publication number: 20160245364
    Abstract: Swirl chamber units (31) allowing a first liquid chamber (14) and a second liquid chamber (15) to communicate with each other are formed in a partitioning member of a vibration-damping device (10) of the present invention. Each swirl chamber unit (31) includes a first communication hole (32a) opening to the first liquid chamber (14), and a second communication hole (32b) opening to the second liquid chamber (15); a first swirl chamber (33a) communicating with the first liquid chamber (14) via the first communication hole (32a), and a second swirl chamber (33b) communicating with the second liquid chamber (15) via the second communication hole (32b); and a flow regulation passage (34) that allows the first swirl chamber (33a) and the second swirl chamber (33b) to communicate with each other and opens to the swirl chambers (33a, 33b) in circumferential directions of the respective swirl chambers (33a, 33b).
    Type: Application
    Filed: October 15, 2014
    Publication date: August 25, 2016
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Akira UEKI, Shingo OONO, Hirokazu WATAI, Masakazu NAGASAWA
  • Publication number: 20140032044
    Abstract: A rotational signal of a generation source of a control object is detected and, when a rotational speed (frequency) varies, convergence values of filter coefficients of adaptive filters 33, 34 based on a previous control result corresponding to the frequency stored in a control device 11 are retrieved and set to the adaptive filters 33, 34 as initial values. The adaptive filters 33, 34 are updated by using the initial values of filter coefficients and output a control signal y(t) to an ACM (actuator) 3a. LMS arithmetic units 37, 39 read a reference signal calculated from the rotational signal and an acceleration signal (error signal) e(t) detected by a sensor 9 and carry out processing for updating the filter coefficients of the adaptive filters 33, 34. The adaptive filters 33, 34, based on updated filter coefficients, output the control signal y(t) to the ACM 3a.
    Type: Application
    Filed: March 13, 2012
    Publication date: January 30, 2014
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Hirokazu Watai, Kazutomo Murakami
  • Publication number: 20100121528
    Abstract: In order to further improve driving stability, a dumper 10 mounted in a vehicle 14 in which a drive unit 11 having an engine 11a and a drive shaft 12 having tires 13 connected to respective end portions in the axial direction thereof, to which drive shaft torque is transferred from the engine 11a, are provided in a vehicle body frame 2, comprises: a connection part 16 for connecting the drive unit 11 with the vehicle body frame; a detection means 17 for detecting variation of torque transferred from the drive unit 11 to the drive shaft 12; and a controller 18 for controlling at least roll vibration of vibration behaviors of the drive unit 11 by operating the connection part 16 on the basis of a detection signal from the detection means 17.
    Type: Application
    Filed: April 23, 2008
    Publication date: May 13, 2010
    Applicant: BRIDGESTONE CORPORATION
    Inventors: Yasuhiro Suzuki, Hironori Adachi, Masanori Ooishi, Kazutomo Murakami, Katsuhiro Kobayashi, Hirokazu Watai