Patents by Inventor Wataru Yokoyama
Wataru Yokoyama 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: 10442413Abstract: A parking brake control apparatus 20 drives an electric motor 43B to advance a piston 39 according to an application request signal from a parking brake switch 19. The parking brake control apparatus 20 includes a running state detection portion that calculates a running state about whether a vehicle is running or stopped based on a wheel signal from a wheel speed sensor 18. When the running state cannot be calculated by the running state detection portion, the parking brake control apparatus 20 controls the electric motor 43B in such a manner that the thrust force of the piston 39 changes at a lower time rate of change than when the running state can be calculated.Type: GrantFiled: March 22, 2016Date of Patent: October 15, 2019Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Yuki Tanaka, Wataru Yokoyama, Kimio Nishino, Masayoshi Okamiya, Kenichiro Matsubara
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Patent number: 10300895Abstract: A brake device having an electric parking brake function, capable of appropriately performing stepwise increase control for a clamping force. A control unit including a computing circuit (20), a memory (21), and each motor drive circuit (23) of a parking brake control device (19) includes a stepwise increase control unit configured to increase the clamping force generated by brake pads (33) to a disc rotor (4) in a stepwise manner. When start of contact between the disc rotor (4) and the brake pads (33) caused by feeding of power from the parking brake control device (19) to an electric motor (43B) is detected based on a motor current from a current sensor unit (24), the stepwise increase control unit performs control for repeatedly feeding and stopping power to the electric motor (43B) to increase the clamping force in a stepwise manner in accordance with a predefined processing procedure.Type: GrantFiled: December 25, 2015Date of Patent: May 28, 2019Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Tatsuro Kobune, Wataru Yokoyama, Kenichiro Matsubara
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Patent number: 10293800Abstract: A parking brake controller (19) activates an electric actuator (43) in response to operation of a parking switch (18) to hold a disc brake (31) to serve as a parking brake. If a failure (fault) is detected in the parking switch (18), the parking brake controller (19) activates the electric actuator (43) so as to hold the parking brake automatically upon detecting a condition that presumes the vehicle operator's intent not to drive any longer while the vehicle is at rest.Type: GrantFiled: December 26, 2014Date of Patent: May 21, 2019Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Wataru Yokoyama, Kimio Nishino, Kenichiro Matsubara, Hiroshi Chikuma, Kenji Hashida
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Patent number: 10232834Abstract: Provided is a brake device capable of maintaining pads and a rotor in a desired positional relationship. When receiving a release request within a time period from start of execution of an application request to detection of contact between brake pad and a disc rotor, a parking brake control device inhibits execution of the release request, and executes the release request after detection of the contact between the brake pad and the disc rotor. Further, when receiving the application request within a time period from start of execution of the release request to detection of separation between the brake pad and the disc rotor, the parking brake control device inhibits execution of the application request, and executes the application request after detection of the separation between the brake pad and the disc rotor.Type: GrantFiled: December 25, 2015Date of Patent: March 19, 2019Assignees: MAZDA MOTOR CORPORATION, HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Michiharu Okada, Shigeyuki Uehara, Tatsuro Kobune, Wataru Yokoyama, Kimio Nishino, Kenichiro Matsubara
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Patent number: 10001183Abstract: A brake apparatus comprising: a caliper having a piston configured to move a brake pad to be pressed on a disc rotor rotating with a wheel; a thrust retaining mechanism located in the caliper to thrust the piston and maintain braking force exerted by the thrust piston; an electric motor mounted on the caliper to operate the thrust retaining mechanism; and a controller configured to apply electric current to the electric motor in response to an application command or a release command, thereby perform control according to the commands, wherein the controller, upon receiving a release command, configured to operate the electric motor to reduce braking force exerted by the piston by performing current maintenance control which continuously applies electric current to the electric motor and switching control which successively switches between a larger and a smaller amount of electric current applied to the electric motor.Type: GrantFiled: July 30, 2015Date of Patent: June 19, 2018Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Kimio Nishino, Kenichiro Matsubara, Wataru Yokoyama, Tatsuro Kobune, Hirotaka Oikawa
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Patent number: 9934626Abstract: Provided is an engagement position storage device capable of detecting a clutch engagement position of a vehicle finely and a brake system including such a device. In an engagement position storage device 2b that stores an engagement position of a clutch to engage and disengage power of a vehicle, when the vehicle becomes a traveling state in predetermined duration after acceleration in a front-back direction of the vehicle changes, the engagement position storage device 2b stores a clutch engagement position based on a clutch position detected when the acceleration changes. A brake system 1 includes a wheel latching mechanism 5 that latches wheels of a vehicle by driving a propelling member 5a by driving devices 3 and 4; and a controller 2 that controls driving of the propelling member 5a of the wheel latching mechanism 5 based on a clutch engagement position stored in the engagement position storage device 2b.Type: GrantFiled: August 29, 2013Date of Patent: April 3, 2018Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Shinji Seto, Masaki Kanai, Wataru Yokoyama
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Publication number: 20180072285Abstract: A parking brake control apparatus 20 drives an electric motor 43B to advance a piston 39 according to an application request signal from a parking brake switch 19. The parking brake control apparatus 20 includes a running state detection portion that calculates a running state about whether a vehicle is running or stopped based on a wheel signal from a wheel speed sensor 18. When the running state cannot be calculated by the running state detection portion, the parking brake control apparatus 20 controls the electric motor 43B in such a manner that the thrust force of the piston 39 changes at a lower time rate of change than when the running state can be calculated.Type: ApplicationFiled: March 22, 2016Publication date: March 15, 2018Inventors: Yuki TANAKA, Wataru YOKOYAMA, Kimio NISHINO, Masayoshi OKAMIYA, Kenichiro MATSUBARA
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Publication number: 20170369047Abstract: An electric brake system includes at least a pair of braking apparatuses each configured to advance a piston for pressing a frictional member against a rotational member rotatable together with a wheel and configured to press the frictional member against the rotational member with use of an electric mechanism according to a braking request signal and hold a pressing force of the frictional member. The electric brake system further includes a control apparatus configured to control the electric mechanism of each of the brake apparatuses and diagnose the failed state in which an abnormality has occurred in each of the brake apparatuses according to the braking request signal. The control apparatus is configured to, when any one of the brake apparatuses is diagnosed as being in the failed state, prohibit the electric mechanism of the one of the brake apparatuses from operating while the vehicle is running.Type: ApplicationFiled: December 25, 2015Publication date: December 28, 2017Inventors: Michiharu OKADA, Shigeyuki UEHARA, Hiroaki KAWAI, Wataru YOKOYAMA
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Publication number: 20170355356Abstract: Provided is a brake device capable of maintaining pads and a rotor in a desired positional relationship. When receiving a release request within a time period from start of execution of an application request to detection of contact between brake pad and a disc rotor, a parking brake control device inhibits execution of the release request, and executes the release request after detection of the contact between the brake pad and the disc rotor. Further, when receiving the application request within a time period from start of execution of the release request to detection of separation between the brake pad and the disc rotor, the parking brake control device inhibits execution of the application request, and executes the application request after detection of the separation between the brake pad and the disc rotor.Type: ApplicationFiled: December 25, 2015Publication date: December 14, 2017Inventors: Michiharu OKADA, Shigeyuki UEHARA, Tatsuro KOBUNE, Wataru YOKOYAMA, Kimio NISHINO, Kenichiro MATSUBARA
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Publication number: 20170291585Abstract: A brake device having an electric parking brake function, capable of appropriately performing stepwise increase control for a clamping force. A control unit including a computing circuit (20), a memory (21), and each motor drive circuit (23) of a parking brake control device (19) includes a stepwise increase control unit configured to increase the clamping force generated by brake pads (33) to a disc rotor (4) in a stepwise manner. When start of contact between the disc rotor (4) and the brake pads (33) caused by feeding of power from the parking brake control device (19) to an electric motor (43B) is detected based on a motor current from a current sensor unit (24), the stepwise increase control unit performs control for repeatedly feeding and stopping power to the electric motor (43B) to increase the clamping force in a stepwise manner in accordance with a predefined processing procedure.Type: ApplicationFiled: December 25, 2015Publication date: October 12, 2017Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Tatsuro KOBUNE, Wataru YOKOYAMA, Kenichiro MATSUBARA
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Patent number: 9714014Abstract: An electric brake apparatus includes an electric actuator configured to actuate a brake mechanism according to an actuation request signal, and an actuator controller configured to control an operation of the electric actuator with use of a power source mounted at a vehicle to perform control of holding and a release of braking by the brake mechanism. When a system recovers and the actuator controller detects that the control of the holding or the release has been interrupted with an uncompleted control state since system down occurred in the middle of the control of the holding or the release of the braking by the brake mechanism, the actuator controller maintains the interrupted state until a new actuation request signal is issued, and controls the operation of the electric actuator according to the content of the new actuation request signal.Type: GrantFiled: March 25, 2015Date of Patent: July 25, 2017Assignees: HITACHI AUTOMOTIVE SYSTEMS, LTD., MAZDA MOTOR CORPORATIONInventors: Michiharu Okada, Shigeyuki Uehara, Kenji Hashida, Wataru Yokoyama, Kenichiro Matsubara
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Patent number: 9670891Abstract: There is provided a power supply for a vehicle, including a generator, a lead battery, an electric storage device that is connected in parallel to the lead battery and to the generator, a starter circuit that has a capacitor and a starter and is connected in parallel to the lead battery and to the generator, and at least two switches of a first switch connected in series to the lead battery, a second switch connected in series to the power supply, and a third switch connected in series to the starter circuit.Type: GrantFiled: July 31, 2015Date of Patent: June 6, 2017Assignee: KABUSHIKI KAISHA TOYOTA JIDOSHOKKIInventors: Keiji Miyake, Katsuyoshi Fujita, Kazuyoshi Takada, Wataru Yokoyama
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Publication number: 20160339888Abstract: A parking brake controller 19 activates an electric actuator 43 in response to operation of a parking switch 18 to hold a disc brake 31 to serve as a parking brake. If a failure (fault) is detected in the parking switch 18, the parking brake controller 19 activates the electric actuator 43 so as to hold the parking brake automatically upon detecting a condition that presumes the vehicle operator's intent not to drive any longer while the vehicle is at rest.Type: ApplicationFiled: December 26, 2014Publication date: November 24, 2016Inventors: Wataru YOKOYAMA, Kimio NISHINO, Kenichiro MATSUBARA, Hiroshi CHIKUMA, Kenji HASHIDA
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Patent number: 9457783Abstract: A disk brake is configured as a brake apparatus provided with an electric parking brake function capable of holding braking of a vehicle by driving an electric actuator. A parking brake control apparatus, which controls the electric actuator, actuates the electric actuator so as to release holding of the braking upon determining that the vehicle is in a running state. More specifically, if a speed of the vehicle is maintained at a speed higher than 0 km/h for a predetermined time period, the parking brake control apparatus actuates a rotation/linear motion conversion mechanism by the electric actuator so as to release the holding of the piston of the disk brake.Type: GrantFiled: December 20, 2013Date of Patent: October 4, 2016Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Tomoyuki Kotake, Wataru Yokoyama, Kenichiro Matsubara
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Patent number: 9434368Abstract: When a controller (19) is restarted after system control has ended, a brake apparatus drives an electric motor (43) so as to achieve a corrected target thrust force calculated by setting a greater thrust force than a target thrust force set according to a temperature estimated value of a frictional member at this time, based on the temperature estimated value of the frictional member at the time of the end of the control, or drives the electric motor based on the temperature estimated value of the frictional member at the time of the end of the control.Type: GrantFiled: August 13, 2014Date of Patent: September 6, 2016Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Tomohiro Ohara, Wataru Yokoyama, Kenji Hashida, Kimio Nishino, Kenichiro Matsubara
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Patent number: 9387845Abstract: 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: GrantFiled: November 28, 2012Date of Patent: July 12, 2016Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventors: Wataru Yokoyama, Takayasu Sakashita, Jun Watanabe
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Patent number: 9387837Abstract: A brake device capable of appropriately releasing a pressing-member retention mechanism when a failure is detected. When a failure of one of a pair of disc brakes (31) is detected, an electric actuator (43) of the non-faulty disc brake (31) is driven to a release side in response to a release request based on a parking brake switch (18) in a case where a state of the faulty disc brake (31) is stored as a “released state” in a storage section (19A) of a parking brake control device (19). In contrast, in a case where the state of the faulty disc brake (31) is stored as an “engaged state” in the storage section (19A), the electric actuator (43) of the non-faulty disc brake (31) is inhibited from being driven to the release side even when the release request based on the parking brake switch (18) is issued.Type: GrantFiled: November 21, 2013Date of Patent: July 12, 2016Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.Inventor: Wataru Yokoyama
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Publication number: 20160040642Abstract: There is provided a power supply for a vehicle, including a generator, a lead battery, an electric storage device that is connected in parallel to the lead battery and to the generator, a starter circuit that has a capacitor and a starter and is connected in parallel to the lead battery and to the generator, and at least two switches of a first switch connected in series to the lead battery, a second switch connected in series to the power supply, and a third switch connected in series to the starter circuit.Type: ApplicationFiled: July 31, 2015Publication date: February 11, 2016Applicant: KABUSHIKI KAISHA TOYOTA JIDOSHOKKIInventors: Keiji MIYAKE, Katsuyoshi FUJITA, Kazuyoshi TAKADA, Wataru YOKOYAMA
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Publication number: 20160032995Abstract: A brake apparatus comprising: a caliper having a piston configured to move a brake pad to be pressed on a disc rotor rotating with a wheel; a thrust retaining mechanism located in the caliper to thrust the piston and maintain braking force exerted by the thrust piston; an electric motor mounted on the caliper to operate the thrust retaining mechanism; and a controller configured to apply electric current to the electric motor in response to an application command or a release command, thereby perform control according to the commands, wherein the controller, upon receiving a release command, configured to operate the electric motor to reduce braking force exerted by the piston by performing current maintenance control which continuously applies electric current to the electric motor and switching control which successively switches between a larger and a smaller amount of electric current applied to the electric motor.Type: ApplicationFiled: July 30, 2015Publication date: February 4, 2016Inventors: Kimio NISHINO, Kenichiro MATSUBARA, Wataru YOKOYAMA, Tatsuro KOBUNE, Hirotaka OIKAWA
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Publication number: 20150274139Abstract: An electric brake apparatus includes an electric actuator configured to actuate a brake mechanism according to an actuation request signal, and an actuator controller configured to control an operation of the electric actuator with use of a power source mounted at a vehicle to perform control of holding and a release of braking by the brake mechanism. When a system recovers and the actuator controller detects that the control of the holding or the release has been interrupted with an uncompleted control state since system down occurred in the middle of the control of the holding or the release of the braking by the brake mechanism, the actuator controller maintains the interrupted state until a new actuation request signal is issued, and controls the operation of the electric actuator according to the content of the new actuation request signal.Type: ApplicationFiled: March 25, 2015Publication date: October 1, 2015Inventors: Michiharu OKADA, Shigeyuki UEHARA, Kenji HASHIDA, Wataru YOKOYAMA, Kenichiro MATSUBARA