Patents by Inventor Masatoshi Nakatsu
Masatoshi Nakatsu 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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Publication number: 20100107791Abstract: In a steering apparatus, a differential lock mechanism has a lock holder in which a plurality of groove portions are formed on an outer periphery thereof, and selectively allows and prohibits to generate a difference of steering amount in the rotational direction between an input shaft and an output shaft by selectively engaging and disengaging an engaging portion with respect to the groove portions. A rotation sensor detects the position in the rotational direction of the lock holder during one rotation of the lock holder and repeatedly detects the same sensor pattern being output a plurality of times. A variable transfer ratio unit ECU detects which groove portion, from among the plurality of groove portions, the engaging portion is engaged with using the sensor pattern output by the rotation sensor when a side portion of one of the groove portions is pressing against a side portion of the engaging portion.Type: ApplicationFiled: January 13, 2010Publication date: May 6, 2010Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Masatoshi NAKATSU
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Patent number: 7681688Abstract: In a steering apparatus, a differential lock mechanism has a lock holder in which a plurality of groove portions are formed on an outer periphery thereof, and selectively allows and prohibits to generate a difference of steering amount in the rotational direction between an input shaft and an output shaft by selectively engaging and disengaging an engaging portion with respect to the groove portions. A rotation sensor detects the position in the rotational direction of the lock holder during one rotation of the lock holder and repeatedly detects the same sensor pattern being output a plurality of times. A variable transfer ratio unit ECU detects which groove portion, from among the plurality of groove portions, the engaging portion is engaged with using the sensor pattern output by the rotation sensor when a side portion of one of the groove portions is pressing against a side portion of the engaging portion.Type: GrantFiled: March 9, 2007Date of Patent: March 23, 2010Assignee: Toyota Jidosha Kabushiki KaishaInventor: Masatoshi Nakatsu
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Publication number: 20100004823Abstract: A vehicle steering control system includes a variable transmission ratio device that rotates an output shaft relative to an input shaft so as to change the transmission ratio, and a locking device that is switched between a lock-on state in which the transmission ratio between the input shaft and the output shaft is inhibited from being changed and a lock-off state in which the transmission ratio between the input shaft and the output shaft is allowed to be changed. The variable transmission ratio device includes an electric motor and a speed reduction mechanism. The locking device inhibits the input shaft and a rotor of the electric motor from rotating relative to each other when placed in the lock-on state, and allows the input shaft and the rotor to rotate relative to each other when placed in the lock-off state.Type: ApplicationFiled: April 9, 2008Publication date: January 7, 2010Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Masatoshi Nakatsu
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Patent number: 7520367Abstract: A steering handle 11 is connected to a front-left wheel FW1 via first and second steering shafts 12 and 13, a pinion gear 14 and a rack bar 31. The pinion gear 14 is connected to a front-right wheel FW2 via third to fifth steering shafts 15, 16 and 23, a pinion gear 24 and a rack bar 34. A first differential gear mechanism 40 is interposed between the first and second steering shafts 12 and 13, whereby the rotation of an electric motor 49 realizes the difference in the rotation between the input shaft and the output shaft of the first differential gear mechanism 40. A second differential gear mechanism 50 is interposed between the third and fourth steering shafts 15 and 16, whereby the rotation of an electric motor 59 realizes the difference in the rotation between the input shaft and the output shaft of the second differential gear mechanism 50. Therefore, the pair of left and right steering wheels FW1, FW2 are steered independently, thereby enhancing maneuverability of a vehicle.Type: GrantFiled: March 31, 2005Date of Patent: April 21, 2009Assignee: Toyota Jidosha Kabushiki KaishaInventors: Masatoshi Nakatsu, Hiroshi Kawakami, Norikazu Hayashi
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Publication number: 20080184838Abstract: In a steering device (200), a first motor (34a) operates in accordance with a steering operation of a steering handle (12), a first steering shaft (52) steers one of the pair of wheels (58), and a first conversion unit converts a rotation of a first rotor (31a) as a rotation element of the first motor (31a) into an axial-direction movement of the first steering shaft (52). A second motor (34b) operates in accordance with the steering operation of the steering handle (12), a second steering shaft (53) is separated from the first steering shaft (52) and steers the other of the pair of wheels (58), and a second conversion unit converts a rotation of a second rotor (31b) as a rotation element of the second motor (34b) into an axial-direction movement of the second steering shaft (53). A coupling unit (60) couples the first rotor (31a) and the second rotor (31b) together and cancels the coupling of the first rotor (31a) and the second rotor (31b).Type: ApplicationFiled: February 7, 2006Publication date: August 7, 2008Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kenji Hayashi, Masatoshi Nakatsu
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Publication number: 20070228715Abstract: In a steering apparatus, a differential lock mechanism has a lock holder in which a plurality of groove portions are formed on an outer periphery thereof, and selectively allows and prohibits to generate a difference of steering amount in the rotational direction between an input shaft and an output shaft by selectively engaging and disengaging an engaging portion with respect to the groove portions. A rotation sensor detects the position in the rotational direction of the lock holder during one rotation of the lock holder and repeatedly detects the same sensor pattern being output a plurality of times. A variable transfer ratio unit ECU detects which groove portion, from among the plurality of groove portions, the engaging portion is engaged with using the sensor pattern output by the rotation sensor when a side portion of one of the groove portions is pressing against a side portion of the engaging portion.Type: ApplicationFiled: March 9, 2007Publication date: October 4, 2007Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Masatoshi Nakatsu
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Patent number: 7121378Abstract: A transfer ratio varying apparatus includes: a steering shaft configured to transmit a steering angle, an actuator connected to the steering shaft and a damper disposed between the input shaft and the steering shaft and configured to absorb vibration caused by the actuator. The actuator includes: a housing, an input shaft configured to integrally rotate with the housing and connected to the steering shaft, a motor including a rotatable shaft, an output shaft configured to transmit an angle to a wheel assembly, and a gear mechanism between the rotatable shaft and the output shaft at the housing, configured to adjust a rotational angle of the rotatable shaft and to output the adjusted rotational angle to the output shaft.Type: GrantFiled: October 29, 2003Date of Patent: October 17, 2006Assignee: Toyoda Koki Kabushiki KaishaInventors: Isao Hasegawa, Osamu Watanabe, Motoyasu Yamamori, Morihiro Matsuda, Shoichi Shono, Masatoshi Nakatsu
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Patent number: 7031813Abstract: An electric steering control device is provided which is capable of enabling the driver to perform steering manipulation stably without being substantially affected by the ambient temperature and the heat generation of the control device. The control device comprises a temperature sensor for detecting the temperature of a circuit board mounting a motor drive circuit thereon and a compensation section for compensating an electric current command value based on the board temperature detected by the temperature sensor, so that en electric motor for exerting an assist force on a vehicle steering mechanism is driven by the compensated electric current command value output from a motor drive circuit. Therefore, the steering operation can be done stably without being substantially affected by the ambient temperature and the heat generation of the control device.Type: GrantFiled: November 14, 2003Date of Patent: April 18, 2006Assignees: Toyoda Koki Kabushiki Kaisha, Toyota Jidosha Kabushiki KaishaInventors: Michiyuki Sugiyama, Hirozumi Eki, Kazumasa Kodama, Junji Kawamuro, Takahiro Kojo, Masatoshi Nakatsu
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Patent number: 7028804Abstract: In a neutral position detection error protecting apparatus, vehicle wheel velocities of right/left driven wheels are detected and a right/left wheel velocity difference is obtained. Then, when a right/left wheel velocity difference is less than a predetermined velocity a steering rotation angle is more than a predetermined value and a vehicle wheel velocity is more than a predetermined velocity in a predetermined period, it is determined that there is an abnormality in the vehicle wheel velocities.Type: GrantFiled: June 18, 2003Date of Patent: April 18, 2006Assignee: Toyoda Koki Kabushiki KaishaInventors: Hirozumi Eki, Michiyuki Sugiyama, Junji Kawamuro, Takahiro Kojo, Masatoshi Nakatsu
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Publication number: 20050230179Abstract: A steering handle 11 is connected to a front-left wheel FW1 via first and second steering shafts 12 and 13, a pinion gear 14 and a rack bar 31. The pinion gear 14 is connected to a front-right wheel FW2 via third to fifth steering shafts 15, 16 and 23, a pinion gear 24 and a rack bar 34. A first differential gear mechanism 40 is interposed between the first and second steering shafts 12 and 13, whereby the rotation of an electric motor 49 realizes the difference in the rotation between the input shaft and the output shaft of the first differential gear mechanism 40. A second differential gear mechanism 50 is interposed between the third and fourth steering shafts 15 and 16, whereby the rotation of an electric motor 59 realizes the difference in the rotation between the input shaft and the output shaft of the second differential gear mechanism 50. Therefore, the pair of left and right steering wheels FW1, FW2 are steered independently, thereby enhancing maneuverability of a vehicle.Type: ApplicationFiled: March 31, 2005Publication date: October 20, 2005Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Masatoshi Nakatsu, Hiroshi Kawakami, Norikazu Hayashi
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Patent number: 6922621Abstract: A drive controlling unit includes a final angle position memorizing device for memorizing a final angle position at a time of termination of the vehicle driving operation, an input complete data memorizing device capable of switching the memory content between a first memory condition and a second memory condition. The first memory condition indicates completeness of writing of the final angle position in the final angle position memorizing device. The second memory condition indicates failure in writing the final angle position therein. The input complete data memorizing device is capable of maintaining the memory content even when the vehicle is stationary.Type: GrantFiled: July 25, 2003Date of Patent: July 26, 2005Assignee: Toyoda Koki Kabushiki KaishaInventors: Kazumasa Kodama, Junji Kawamuro, Takahiro Kojo, Masatoshi Nakatsu, Masahiro Miyata
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Patent number: 6904999Abstract: A target relative rotational angle ??t which is created by a steering gear ratio change unit and which is formed by a lower steering shaft relative to an upper steering shaft is calculated on the basis of a steering angle ?, and a post-correction target relative rotational angle ??ta to be created by the steering gear ratio change unit is calculated on the basis of the target relative rotational angle ??t and a vehicle speed range that has been determined on the basis of a vehicle speed V. Thus, a target relative rotational angle in one lateral direction is so corrected as to be equal to or smaller than a difference between a permissible rotational angle to be defined by a spiral cable in the other lateral direction and a maximum possible rotational angle of the lower steering shaft in the other lateral direction. An electric motor is controlled on the basis of the post-correction target relative rotational angle ??ta.Type: GrantFiled: July 9, 2003Date of Patent: June 14, 2005Assignee: Toyota Jidosha Kabushiki KaishaInventors: Takahiro Kojo, Junji Kawamuro, Masatoshi Nakatsu
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Patent number: 6896091Abstract: A vehicular steering control apparatus controls the wheel steering amount of wheels based on a steering angle and an assist angle obtained by multiplying a steering speed by a gain. If the amount of power control differs between the left wheel and the right wheel, the value of gain is increased. The amount of power control includes, for example, the amount of braking control and the amount of drive control. If the assist angle is increased by increasing the gain, the magnitude of the wheel steering amount relative to the steering angle increases, so that a driver can correct the orientation of the vehicle body by performing a small amount of steering operation.Type: GrantFiled: July 3, 2003Date of Patent: May 24, 2005Assignee: Toyota Jidosha Kabushiki KaishaInventors: Takahiro Kojo, Junji Kawamuro, Masatoshi Nakatsu, Masato Suzumura
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Publication number: 20050023072Abstract: A drive controlling means includes a final angle position memorizing means for memorizing a final angle position at a time of termination of the vehicle driving operation, an input complete data memorizing means capable of switching the memory content between a first memory condition and a second memory condition. The first memory condition indicates completeness of writing of the final angle position in the final angle position memorizing means. The second memory condition indicates failure in writing the final angle position therein. The input complete data memorizing means is capable of maintaining the memory content even when the vehicle is stationary.Type: ApplicationFiled: July 25, 2003Publication date: February 3, 2005Applicant: TOYODA KOKI KABUSHIKI KAISHAInventors: Kazumasa Kodama, Junji Kawamuro, Takahiro Kojo, Masatoshi Nakatsu, Masahiro Miyata
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Patent number: 6843344Abstract: A PWM control includes a first PWM control and a second PWM control. In the first PWM control, a first power supply terminal of a first coil is kept non-switched under being connected to a first pole of a direct current power source, and a second power supply terminal of a second coil is capable of being switched under being connected to a second pole of the direct current power source. The second PWM control is performed by switching a first connected condition and a second connected condition by turns. The first connected condition is established with the first power supply terminal connected to the first pole and the second power supply terminal connected to the second pole. The second connected condition is established with the first power supply terminal being connected to the second pole and the second power supply terminal being connected to the first pole.Type: GrantFiled: July 25, 2003Date of Patent: January 18, 2005Assignee: Toyoda Koki Kabushiki KaishaInventors: Kazumasa Kodama, Yutaka Mori, Junji Kawamuro, Takahiro Kojo, Masatoshi Nakatsu
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Patent number: 6840347Abstract: A vehicle steering apparatus is provided with a transmitting ratio variable gear ratio mechanism in a steering force transmitting system, and a lock mechanism which limits relative rotation between an input shaft and an output shaft of the steering force transmitting system. In the lock mechanism is provided a lock holder which rotates together with a rotor of a motor, and in which is formed a plurality of first indented portions in a circumferential direction along the circumference and a second indented portion indented deeper than the first indented portions at one end portion of each of the first indented portions. In the lock mechanism is also provided a lock arm which is provided on a stator side of the motor and which engages with the one of the first indented portions or second indented portions.Type: GrantFiled: July 15, 2003Date of Patent: January 11, 2005Assignee: Toyota Jidosha Kabushiki KaishaInventors: Masatoshi Nakatsu, Junji Kawamuro, Takahiro Kojo
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Patent number: 6834742Abstract: A vehicle steering apparatus includes a variable gear ratio mechanism which is provided in a steering force transmitting system, and a lock mechanism which restricts relative rotation of an input shaft and an output shaft of the transmitting ratio changing mechanism. The lock mechanism is engaged by inserting a lock arm in a indented portion of a lock holder of the lock mechanism. A play angle when the lock mechanism is engaged by inserting the lock arm in the indented portion is set to be smaller than a rotational angle of a motor which is required for outputting six different signals.Type: GrantFiled: July 9, 2003Date of Patent: December 28, 2004Assignee: Toyota Jidosha Kabushiki KaishaInventors: Masatoshi Nakatsu, Junji Kawamuro, Takahiro Kojo
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Publication number: 20040206569Abstract: A PWM control includes a first PWM control and a second PWM control. In the first PWM control, a first power supply terminal of a first coil is kept non-switched under being connected to a first pole of a direct current power source, and a second power supply terminal of a second coil is capable of being switched under being connected to a second pole of the direct current power source. The second PWM control is performed by switching a first connected condition and a second connected condition by turns. The first connected condition is established with the first power supply terminal connected to the first pole and the second power supply terminal connected to the second pole. The second connected condition is established with the first power supply terminal being connected to the second pole and the second power supply terminal being connected to the first pole.Type: ApplicationFiled: July 25, 2003Publication date: October 21, 2004Applicant: TOYODA KOKI KABUSHIKI KAISHAInventors: Kazumasa Kodama, Yutaka Mori, Junji Kawamuro, Takahiro Kojo, Masatoshi Nakatsu
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Patent number: 6801840Abstract: A angle sensor 103 identifies a angle phase of a rotatable member based on a kind of an identified pattern of the angle phase to detect an angular position of a steering shaft driven by a motor 6. A steering controller 100 identifies a rotational direction based on an identified pattern output of the angle and performs a sampling of the pattern output at a predetermined interval, identifies an order of combination order of the identified pattern of an angle phase in a first sampling and a second sampling following to the first sampling, and determines a pattern exchange number with the rotational direction from the order in the first sampling to the order in the second sampling.Type: GrantFiled: July 25, 2003Date of Patent: October 5, 2004Assignee: Toyoda Koki Kabushiki KaishaInventors: Kazumasa Kodama, Junji Kawamuro, Takahiro Kojo, Masatoshi Nakatsu
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Publication number: 20040148076Abstract: A angle sensor 103 identifies a angle phase of a rotatable member based on a kind of an identified pattern of the angle phase to detect an angular position of a steering shaft driven by a motor 6. A steering controller 100 identifies a rotational direction based on an identified pattern output of the angle and performs a sampling of the pattern output at a predetermined interval, identifies an order of combination order of the identified pattern of an angle phase in a first sampling and a second sampling following to the first sampling, and determines a pattern exchange number with the rotational direction from the order in the first sampling to the order in the second sampling.Type: ApplicationFiled: July 25, 2003Publication date: July 29, 2004Applicant: TOYODA KOKI KABUSHIKI KAISHAInventors: Kazumasa Kodama, Junji Kawamuro, Takahiro Kojo, Masatoshi Nakatsu