Patents by Inventor Takayasu Sakashita

Takayasu Sakashita 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: 20210039620
    Abstract: To provide a disc brake having a planetary gear reduction mechanism that may be satisfactory costly and achieve improved reliability, a planetary gear reduction mechanism of a disc brake according to the present disclosure includes a sun gear having an input gear portion to which rotation from a motor is transmitted and an output gear portion extending axially from a radial central region of the input gear portion, a plurality of planetary gears configured to mesh with the output gear portion of the sun gear, and an internal gear configured to mesh with each planetary gear, and the internal gear has a cylindrical support portion configured to rotatably support the sun gear. Accordingly, at the time of assembly, the axis of the sun gear and the axis of the internal gear may be arranged substantially concentrically, which may result in improved reliability and cost satisfaction.
    Type: Application
    Filed: March 27, 2019
    Publication date: February 11, 2021
    Inventors: Takashi MITSUGI, Daisuke HIBI, Takayasu SAKASHITA, Jun WATANABE, Rikiya YOSHIZU, Atsushi ODAIRA, Takuya USUI
  • Patent number: 10626941
    Abstract: A disc brake including a piston driving mechanism. The piston driving mechanism includes an input member extended in a cylinder in a protruding direction of a piston, including a threaded portion formed on a circumferential surface of the input member, and configured to be rotated with transmission of torque from an electric motor; a tubular rotation linear motion member including an engaging threaded portion that is engaged with the threaded portion of the input member, and configured to move in an axial direction of the cylinder by rotation of the input member to transmit a torque of the electric motor to the piston; a tubular support member supported on a caliper main body to be not rotatable and placed on an outer side in a radial direction with respect to the rotation linear motion member; and a rolling element placed between the support member and the rotation linear motion member.
    Type: Grant
    Filed: June 1, 2017
    Date of Patent: April 21, 2020
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventor: Takayasu Sakashita
  • Publication number: 20190249734
    Abstract: A disc brake including a piston driving mechanism. The piston driving mechanism includes an input member extended in a cylinder in a protruding direction of a piston, including a threaded portion formed on a circumferential surface of the input member, and configured to be rotated with transmission of torque from an electric motor; a tubular rotation linear motion member including an engaging threaded portion that is engaged with the threaded portion of the input member, and configured to move in an axial direction of the cylinder by rotation of the input member to transmit a torque of the electric motor to the piston; a tubular support member supported on a caliper main body to be not rotatable and placed on an outer side in a radial direction with respect to the rotation linear motion member; and a rolling element placed between the support member and the rotation linear motion member.
    Type: Application
    Filed: June 1, 2017
    Publication date: August 15, 2019
    Inventor: Takayasu SAKASHITA
  • Patent number: 9902378
    Abstract: An object of the present invention is to obtain a brake system that can generate appropriate braking force without influence of temperature. A brake system includes: a piston that presses pressing members; a motor that moves the piston; a current detection unit that detects current flowing in the motor; a storage unit that stores a correspondence relation between idle running current and motor stopping current; a motor stopping current setting unit that sets the motor stopping current using the storage unit and the idle running current; and a control unit that stops to supply the current to the motor when the current flowing in the motor reaches the motor stopping current. The correspondence relation is set so that the rate of change of the motor stopping current relative to the idle running current becomes smaller when the idle running current is small than that when it is large.
    Type: Grant
    Filed: August 24, 2015
    Date of Patent: February 27, 2018
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Shinji Seto, Tatsuro Kobune, Takayasu Sakashita
  • Patent number: 9731693
    Abstract: A disk brake apparatus includes a piston thrust mechanism disposed in a caliper and including a thrust member configured to thrust a piston by an electric motor, and a piston holding mechanism configured to hold the thrust piston. When the piston holding mechanism release the holding of the thrust piston, the controller acquires a hydraulic pressure supplied to the caliper. If the hydraulic pressure is a predetermined value or higher, the controller determines whether a thrust force generated by the electric motor is released based on a time period from issue of an instruction to release the holding of the piston and a start of driving of the electric motor. If the hydraulic pressure is lower than the predetermined value, the controller determines whether the thrust force generated by the electric motor is released based on a change status of a current for driving the electric motor.
    Type: Grant
    Filed: September 23, 2013
    Date of Patent: August 15, 2017
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takayasu Sakashita, Hirotaka Oikawa
  • Patent number: 9568058
    Abstract: A rotary-to-linear conversion mechanism includes a rotation transmission member, a shaft member threadedly fitted to the rotation transmission member so that a rotation and linear motion of the shaft member are enabled, and a ball-and-ramp mechanism threadedly fitted to the shaft member, which is configured to apply a thrust in the axial direction to a piston through the rotation of the shaft member. The shaft member includes a first thread formed on one end side thereof, and a second thread formed on the other end side thereof. A rotation friction torque of the first thread is larger than a rotation friction torque of the second thread.
    Type: Grant
    Filed: July 21, 2015
    Date of Patent: February 14, 2017
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takayasu Sakashita, Yuki Naito
  • Patent number: 9500240
    Abstract: A disk brake (1) including a connector portion (35) provided at a housing (30). The connector portion (35) includes supply terminals (131) for supplying power to a motor (32). The supply terminals (131) of the connector portion (35) and motor terminals (32C) of the motor (32) are connected to each other via bus bars (130) made of metallic plate. Further, the bus bars (130) are held in a loosely fitted state on another-side surface (138B) of a plate-like portion (138) of a support member (135) attached to the housing (30).
    Type: Grant
    Filed: July 18, 2013
    Date of Patent: November 22, 2016
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takaaki Fuse, Satoru Tsurumi, Jun Watanabe, Takayasu Sakashita
  • Patent number: 9475472
    Abstract: A brake system includes a brake apparatus. This brake apparatus is configured to keep a vehicle braked by an electric mechanism in response to a parking brake request signal, and brake the vehicle by supply of a hydraulic pressure from a hydraulic source in response to an operation performed on a brake pedal. The brake system further includes a controller configured to drive the electric mechanism until a target pressing force is acquired to establish a brake holding state in response to the parking brake request signal. The controller is configured to change the target pressing force according to a change in a hydraulic pressure in the brake apparatus after starting driving the electric mechanism in response to the parking brake request signal.
    Type: Grant
    Filed: August 26, 2014
    Date of Patent: October 25, 2016
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takayasu Sakashita, Hirotaka Oikawa, Kimio Nishino
  • Patent number: 9387845
    Abstract: Upon a start of a release for releasing a braking state of a parking bake in a process of step 2, a control unit (13) performs hydraulic maintaining control by an ESC (11) in a subsequent step, step 3. As a result, a hydraulic pressure in a cylinder portion (46) increases according to a retraction of a piston (49) of a disk brake (41). If the control unit (13) determines in step 4 that the release of the parking brake has been completed, in step 5, the control unit (13) releases the hydraulic maintaining control by the ESC (11). The hydraulic pressure is temporarily increased in the cylinder portion (46) of the disk brake (41), thereby increasing an elastic deformation amount of a piston seal (56) to succeed in acquiring a sufficient rollback function.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: July 12, 2016
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Wataru Yokoyama, Takayasu Sakashita, Jun Watanabe
  • Publication number: 20160052496
    Abstract: An object of the present invention is to obtain a brake system that can generate appropriate braking force without influence of temperature. A brake system includes: a piston that presses pressing members; a motor that moves the piston; a current detection unit that detects current flowing in the motor; a storage unit that stores a correspondence relation between idle running current and motor stopping current; a motor stopping current setting unit that sets the motor stopping current using the storage unit and the idle running current; and a control unit that stops to supply the current to the motor when the current flowing in the motor reaches the motor stopping current. The correspondence relation is set so that the rate of change of the motor stopping current relative to the idle running current becomes smaller when the idle running current is small than that when it is large.
    Type: Application
    Filed: August 24, 2015
    Publication date: February 25, 2016
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Shinji SETO, Tatsuro KOBUNE, Takayasu SAKASHITA
  • Publication number: 20160032994
    Abstract: A rotary-to-linear conversion mechanism includes a rotation transmission member, a shaft member threadedly fitted to the rotation transmission member so that a rotation and linear motion of the shaft member are enabled, and a ball-and-ramp mechanism threadedly fitted to the shaft member, which is configured to apply a thrust in the axial direction to a piston through the rotation of the shaft member. The shaft member includes a first thread formed on one end side thereof, and a second thread formed on the other end side thereof. A rotation friction torque of the first thread is larger than a rotation friction torque of the second thread.
    Type: Application
    Filed: July 21, 2015
    Publication date: February 4, 2016
    Inventors: Takayasu SAKASHITA, Yuki NAITO
  • Patent number: 9086108
    Abstract: A disk brake including a simplified structure for retaining the braking force of a parking brake. The disk brake is equipped with a piston holding mechanism having a ball-and-ramp mechanism in which balls are moved by rotation transmitted from a motor, causing a rotary-rectilinear ramp to press a piston. The rotary-rectilinear ramp has an external thread engaged with an internal thread formed on a base nut that is immovable in a rotor axis direction relative to a caliper body. The external thread, when a force is applied thereto from the piston in the rotor axis direction, can retain the position of the rotary-rectilinear ramp in the rotor axis direction. Thus, the structure for retaining the braking force of the parking brake can be simplified to improve production efficiency.
    Type: Grant
    Filed: March 26, 2012
    Date of Patent: July 21, 2015
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventor: Takayasu Sakashita
  • Publication number: 20150061365
    Abstract: A brake system includes a brake apparatus. This brake apparatus is configured to keep a vehicle braked by an electric mechanism in response to a parking brake request signal, and brake the vehicle by supply of a hydraulic pressure from a hydraulic source in response to an operation performed on a brake pedal. The brake system further includes a controller configured to drive the electric mechanism until a target pressing force is acquired to establish a brake holding state in response to the parking brake request signal. The controller is configured to change the target pressing force according to a change in a hydraulic pressure in the brake apparatus after starting driving the electric mechanism in response to the parking brake request signal.
    Type: Application
    Filed: August 26, 2014
    Publication date: March 5, 2015
    Inventors: Takayasu SAKASHITA, Hirotaka OIKAWA, Kimio NISHINO
  • Publication number: 20140284151
    Abstract: Upon a start of a release for releasing a braking state of a parking bake in a process of step 2, a control unit (13) performs hydraulic maintaining control by an ESC (11) in a subsequent step, step 3. As a result, a hydraulic pressure in a cylinder portion (46) increases according to a retraction of a piston (49) of a disk brake (41). If the control unit (13) determines in step 4 that the release of the parking brake has been completed, in step 5, the control unit (13) releases the hydraulic maintaining control by the ESC (11). The hydraulic pressure is temporarily increased in the cylinder portion (46) of the disk brake (41), thereby increasing an elastic deformation amount of a piston seal (56) to succeed in acquiring a sufficient rollback function.
    Type: Application
    Filed: November 28, 2012
    Publication date: September 25, 2014
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD
    Inventors: Wataru Yokoyama, Takayasu Sakashita, Jun Watanabe
  • Patent number: 8770353
    Abstract: A ball-and-ramp mechanism of a thrust generator includes a rotary ramp member and a rectilinear ramp member, each having a plurality of sloped grooves sloped along a circumferential direction and having an arcuate diametrical cross-section, and a spherical member interposed between the sloped grooves of the ramp members to transmit force from the rotary ramp member to the rectilinear ramp member. Each of the sloped grooves has regions varying in the curvature radius of the diametrical cross-section in a track area where the spherical member contacts the sloped groove. Accordingly, it is possible to improve the durability of the rotary ramp member and the rectilinear ramp member.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: July 8, 2014
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Takuya Usui, Takayasu Sakashita, Atsushi Odaira
  • Publication number: 20140095042
    Abstract: A disk brake apparatus includes a piston thrust mechanism disposed in a caliper and including a thrust member configured to thrust a piston by an electric motor, and a piston holding mechanism configured to hold the thrust piston. When the piston holding mechanism release the holding of the thrust piston, the controller acquires a hydraulic pressure supplied to the caliper. If the hydraulic pressure is a predetermined value or higher, the controller determines whether a thrust force generated by the electric motor is released based on a time period from issue of an instruction to release the holding of the piston and a start of driving of the electric motor. If the hydraulic pressure is lower than the predetermined value, the controller determines whether the thrust force generated by the electric motor is released based on a change status of a current for driving the electric motor.
    Type: Application
    Filed: September 23, 2013
    Publication date: April 3, 2014
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takayasu SAKASHITA, Hirotaka OIKAWA
  • Publication number: 20140090933
    Abstract: Provided is a disc brake with high reliability. In a disc brake (1), pins (60) press-fitted to a carrier (58) are inserted through hole portions (56B) of respective planet gears (56) in a freely rotatable and axially movable manner. Further, axial movement of the carrier (58) is allowed by an amount corresponding to a length of a clearance (37). As a result, when a rotary-to-linear ramp (65) advances during actuation of a parking brake, the carrier (58) and the pins (60) advance together with the rotary-to-linear ramp (65). Thus, actuation efficiency becomes excellent and durability is enhanced.
    Type: Application
    Filed: September 23, 2013
    Publication date: April 3, 2014
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Takayasu SAKASHITA, Jun WATANABE, Satoru TSURUMI, Takaaki FUSE
  • Publication number: 20140034430
    Abstract: An object of the present invention is to provide a highly reliable disk brake. In a disk brake 1 according to the present invention, a connector portion 35 is provided at a housing 30. The connector portion 35 includes supply terminals 131 for supplying power to a motor 32. The supply terminals 131 of the connector portion 35 and motor terminals 32C of the motor 32 are connected to each other via bus bars 130 made of metallic plate. Further, the bus bars 130 are held in a loosely fitted state on another-side surface 138B of a plate-like portion 138 of a support member 135 attached to the housing 30.
    Type: Application
    Filed: July 18, 2013
    Publication date: February 6, 2014
    Inventors: Takaaki FUSE, Satoru TSURUMI, Jun WATANABE, Takayasu SAKASHITA
  • Patent number: 8348023
    Abstract: An object of the present invention is to provide a disk brake having excellent responsiveness. A rotation preventing mechanism 34A prevents a rotation of a carrier 41 (one output member) in a direction causing a piston 12 to return. An internal gear 46 (the other output member) rotates by a predetermined degree to act on the rotation preventing mechanism 34A. When the motor 38 causes a sun gear (input member) to rotate such that the piston 12 moves in a return direction, a rotation of the internal gear 46 according to the rotation of the sun gear 44 releases rotation prevention of the rotation preventing mechanism 34A to the carrier 41. It is possible to release the parking brake without use of a worm gear which is used in the conventional arts for holding a thrust force (self-holding). As a result, it is possible to quickly release the parking brake, and therefore a driver can start to run without delay after parking brake release, whereby the responsiveness is improved.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: January 8, 2013
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Takayasu Sakashita, Jun Watanabe
  • Publication number: 20120261220
    Abstract: Provided is a disk brake improved in production efficiency by simplifying a structure for retaining the braking force of a parking brake. A disk brake is equipped with a piston holding mechanism having a ball-and-ramp mechanism in which balls are moved by rotation transmitted from a motor, causing a rotary-rectilinear ramp to press a piston. The rotary-rectilinear ramp has an external thread engaged with an internal thread formed on a base nut immovable in a rotor axis direction relative to a caliper body. The external thread, when a force is applied thereto from the piston in the rotor axis direction, can retain the position of the rotary-rectilinear ramp in the rotor axis direction. Thus, the structure for retaining the braking force of the parking brake can be simplified to improve the production efficiency.
    Type: Application
    Filed: March 26, 2012
    Publication date: October 18, 2012
    Inventor: Takayasu SAKASHITA