Patents by Inventor Mikihiko Tsunoda
Mikihiko Tsunoda 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: 9557234Abstract: In a torque sensor of an electric power steering device, a natural and comfortable feeling to a driver (driver) is achieved by increasing the physical quantity of the torque sensor around the center of the steering wheel (neutral position). A torsion bar (3) for use in the torque sensor includes a core torsion bar (3A) and a tubular torsion bar (3B). The tubular torsion bar (3B) includes a pair of torsion tubular bar parts (3Ba, 3Bb), accommodates the core torsion bar (3A) in its inside, secures both ends of the core torsion bar (3A) in its inside, and the pair of tubular torsion parts (3Ba, 3Bb) mesh and couple each other by meshing teeth, when the core torsion bar (3A) twists a predefined rotational angle, so that a single torsion bar is configured. The elasticity of the tubular torsion bar (3B) is larger than that of the core torsion bar (3A).Type: GrantFiled: December 22, 2014Date of Patent: January 31, 2017Assignee: NSK Ltd.Inventors: Mikihiko Tsunoda, Tamotsu Oumi
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Patent number: 9457838Abstract: An electric power steering system is provided which can take an abnormality countermeasure without being affected by a torque abnormality signal and without giving an uncomfortable feeling to a driver when torque abnormality occurs. Abnormality of a steering assist command value is detected by employing a dual detection configuration of a main ECU clip (34) and a sub ECU interlock (62). When abnormality of a steering torque Ti detected by a torque sensor (3) is detected, input values to the main ECU clip (34) and the sub ECU interlock (62) are switched from the steering torque Ti detected by the torque sensor (3) to an alternative torque value. Here, the alternative torque value employs a previous torque value calculated based upon the normal steering torque Ti detected by the torque sensor (3) when the abnormality of the steering torque Ti detected by the torque sensor (3) is not detected.Type: GrantFiled: October 24, 2013Date of Patent: October 4, 2016Assignee: NSK Ltd.Inventors: Mikihiko Tsunoda, Mitsunori Okubo, Naoki Sawada
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Publication number: 20160282208Abstract: In a torque sensor of an electric power steering device, a natural and comfortable feeling to a driver (driver) is achieved by increasing the physical quantity of the torque sensor around the center of the steering wheel (neutral position). A torsion bar (3) for use in the torque sensor includes a core torsion bar (3A) and a tubular torsion bar (3B). The tubular torsion bar (3B) includes a pair of torsion tubular bar parts (3Ba, 3Bb), accommodates the core torsion bar (3A) in its inside, secures both ends of the core torsion bar (3A) in its inside, and the pair of tubular torsion parts (3Ba, 3Bb) mesh and couple each other by meshing teeth, when the core torsion bar (3A) twists a predefined rotational angle, so that a single torsion bar is configured. The elasticity of the tubular torsion bar (3B) is larger than that of the core torsion bar (3A).Type: ApplicationFiled: December 22, 2014Publication date: September 29, 2016Inventors: Mikihiko TSUNODA, Tamotsu OUMI
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Patent number: 9365238Abstract: There is provided an electric power steering device capable of detecting steering torque with high accuracy without use of a torque sensor, and capable of performing appropriate steering assistance control. An alternative torque correction value (Tc) is operated by comparing alternative torque (T0) operated based on an angle signal at normal time of the torque sensor (3) with a torque detection value (Ti) detected by the torque sensor (3), and is then stored. Then, at normal time of the torque sensor (3), the steering assistance control is performed based on the torque detection value (Ti) detected by the torque sensor (3), whereas when an abnormality happens in the torque sensor (3), the steering assistance control is performed based on corrected alternative torque (T1) obtained by correcting the alternative torque (T0) by the alternative torque correction value (Tc).Type: GrantFiled: December 16, 2014Date of Patent: June 14, 2016Assignee: NSK Ltd.Inventors: Mikihiko Tsunoda, Tamotsu Oumi
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Patent number: 9352770Abstract: There is provided an electric power steering apparatus capable of dealing with abnormality when the abnormality happens in the torque, without being affected by an abnormal torque signal and without giving the driver a feeling of strangeness. Abnormality is detected with a double detection configuration including a main ECU clip and a sub ECU interlock. Then when abnormality is detected in steering torque detected by a torque sensor, the input of a main ECU clip is switched from the steering torque detected by the torque sensor to a torque alternative value, and the input value of the sub ECU interlock is switched from a steering assist command value subjected to limiting at the main ECU clip to zero.Type: GrantFiled: October 1, 2014Date of Patent: May 31, 2016Assignee: NSK Ltd.Inventors: Mikihiko Tsunoda, Mitsunori Okubo, Tamotsu Oumi
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Publication number: 20160059886Abstract: An electric power steering system is provided which can take an abnormality countermeasure without being affected by a torque abnormality signal and without giving an uncomfortable feeling to a driver when torque abnormality occurs. Abnormality of a steering assist command value is detected by employing a dual detection configuration of a main ECU clip (34) and a sub ECU interlock (62). When abnormality of a steering torque Ti detected by a torque sensor (3) is detected, input values to the main ECU clip (34) and the sub ECU interlock (62) are switched from the steering torque Ti detected by the torque sensor (3) to an alternative torque value. Here, the alternative torque value employs a previous torque value calculated based upon the normal steering torque Ti detected by the torque sensor (3) when the abnormality of the steering torque Ti detected by the torque sensor (3) is not detected.Type: ApplicationFiled: October 24, 2013Publication date: March 3, 2016Inventors: Mikihiko TSUNODA, Mitsunori OKUBO, Naoki SAWADA
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Publication number: 20150367881Abstract: There is provided an electric power steering device capable of detecting steering torque with high accuracy without use of a torque sensor, and capable of performing appropriate steering assistance control. An alternative torque correction value (Tc) is operated by comparing alternative torque (T0) operated based on an angle signal at normal time of the torque sensor (3) with a torque detection value (Ti) detected by the torque sensor (3), and is then stored. Then, at normal time of the torque sensor (3), the steering assistance control is performed based on the torque detection value (Ti) detected by the torque sensor (3), whereas when an abnormality happens in the torque sensor (3), the steering assistance control is performed based on corrected alternative torque (T1) obtained by correcting the alternative torque (T0) by the alternative torque correction value (Tc).Type: ApplicationFiled: December 16, 2014Publication date: December 24, 2015Inventors: Mikihiko TSUNODA, Tamotsu OUMI
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Publication number: 20150274202Abstract: There is provided an electric power steering apparatus capable of dealing with abnormality when the abnormality happens in the torque, without being affected by an abnormal torque signal and without giving the driver a feeling of strangeness. Abnormality is detected with a double detection configuration including a main ECU clip and a sub ECU interlock. Then when abnormality is detected in steering torque detected by a torque sensor, the input of a main ECU clip is switched from the steering torque detected by the torque sensor to a torque alternative value, and the input value of the sub ECU interlock is switched from a steering assist command value subjected to limiting at the main ECU clip to zero.Type: ApplicationFiled: October 1, 2014Publication date: October 1, 2015Applicant: NSK LTD.Inventors: Mikihiko Tsunoda, Mitsunori Okubo, Tamotsu Oumi
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Patent number: 8919489Abstract: Connection terminals are provided for electrically connecting sensor terminals and through holes provided on a control substrate, and a control unit is provided with a frame of synthetic resin for holding the control substrate. The frame of synthetic resin is provided with: a connection terminal holding portion for holding one ends of the connection terminals connected to the through holes partially insert-molded and the other ends protruding outwardly from the frame of synthetic resin; and guide openings for guiding and making the sensor terminals insert therethrough so that the sensor terminals protruding from the outer circumference of the reduction gearbox extend to the position where the sensor terminals are connectable with the other ends of the connection terminals.Type: GrantFiled: September 20, 2011Date of Patent: December 30, 2014Assignee: NSK Ltd.Inventor: Mikihiko Tsunoda
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Patent number: 8659252Abstract: An electric motor and a control unit are juxtaposed in a speed reduction gear box. A terminal block is provided at an outer circumference of a flange proximate to a control unit of the electric motor. Terminal block surfaces of the terminal block are provided so that a plane direction faces a direction vertical to a shaft line of the electric motor. A motor side connecting terminal is held on the terminal block surface. The unit side connecting terminals provided at a position proximate to the electric motor of the control unit are arranged so as to overlap with the motor side connecting terminal on the terminal block surface to couple by a coupling portion (fixing screw).Type: GrantFiled: September 20, 2011Date of Patent: February 25, 2014Assignee: NSK Ltd.Inventors: Takayuki Ochiai, Mikihiko Tsunoda, Naoki Sawada
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Publication number: 20130299269Abstract: Connection terminals are provided for electrically connecting sensor terminals and through holes provided on a control substrate, and a control unit is provided with a frame of synthetic resin for holding the control substrate. The frame of synthetic resin is provided with: a connection terminal holding portion for holding one ends of the connection terminals connected to the through holes partially insert-molded and the other ends protruding outwardly from the frame of synthetic resin; and guide openings for guiding and making the sensor terminals insert therethrough so that the sensor terminals protruding from the outer circumference of the reduction gearbox extend to the position where the sensor terminals are connectable with the other ends of the connection terminals.Type: ApplicationFiled: September 20, 2011Publication date: November 14, 2013Applicant: NSK Ltd.Inventor: Mikihiko Tsunoda
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Publication number: 20130257337Abstract: An electric motor and a control unit are juxtaposed in a speed reduction gear box. A terminal block is provided at an outer circumference of a flange proximate to a control unit of the electric motor. Terminal block surfaces of the terminal block are provided so that a plane direction faces a direction vertical to a shaft line of the electric motor. A motor side connecting terminal is held on the terminal block surface. The unit side connecting terminals provided at a position proximate to the electric motor of the control unit are arranged so as to overlap with the motor side connecting terminal on the terminal block surface to couple by a coupling portion (fixing screw).Type: ApplicationFiled: September 20, 2011Publication date: October 3, 2013Applicant: NSK LTD.Inventors: Takayuki Ochiai, Mikihiko Tsunoda, Naoki Sawada
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Patent number: 7202621Abstract: A power steering control device includes a torque sensor that detects a steering torque and outputs a torque signal having a torque neutral voltage is determined based on a predetermined reference voltage, a reference-voltage generator unit that generates the reference voltage, an A/D converter unit that A/D converts the torque signal and the reference voltage, a calculator unit that calculates a steering assist torque based on the A/D converted torque signal, a current controller unit that supplies a driving current in accordance with the assist torque to a steering assist motor, a reference-voltage generator unit that generates the reference voltage and outputs the reference voltage to the A/D converter unit and a fault diagnosis unit that monitors the A/D converted reference voltage and performs a predetermined fault diagnosis process.Type: GrantFiled: May 11, 2005Date of Patent: April 10, 2007Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventor: Mikihiko Tsunoda
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Publication number: 20050264248Abstract: A power steering control device includes a torque sensor that detects a steering torque and outputs a torque signal having a torque neutral voltage is determined based on a predetermined reference voltage, a reference-voltage generator unit that generates the reference voltage, an A/D converter unit that A/D converts the torque signal and the reference voltage, a calculator unit that calculates a steering assist torque based on the A/D converted torque signal, a current controller unit that supplies a driving current in accordance with the assist torque to a steering assist motor, a reference-voltage generator unit that generates the reference voltage and outputs the reference voltage to the A/D converter unit and a fault diagnosis unit that monitors the A/D converted reference voltage and performs a predetermined fault diagnosis process.Type: ApplicationFiled: May 11, 2005Publication date: December 1, 2005Inventor: Mikihiko Tsunoda