Patents by Inventor Yutaka Taga
Yutaka Taga 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: 7549944Abstract: A control apparatus for a vehicular drive system provided with a step-variable transmission portion operable to transmit an output of an engine to a drive wheel of a vehicle and functioning as a step-variable transmission, and an input clutch operable to permit and inhibit an input of a drive force from the engine to the step-variable transmission portion, the control apparatus including an input-clutch control portion operable to reduce a torque capacity of the input clutch, during a shifting action of the step-variable transmission portion, for limiting a torque to be transmitted to the step-variable transmission portion, to a value not larger than a predetermined value.Type: GrantFiled: June 21, 2006Date of Patent: June 23, 2009Assignee: Toyota Jidosha Kabushiki KaishaInventors: Atsushi Tabata, Yutaka Taga, Yuji Inoue, Atsushi Kamada
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Patent number: 7544140Abstract: A control device for a vehicular drive system including continuously-variable transmission portion 11 and step-variable transmission portion 20, wherein an emergency transmission control device is operated when one of the continuously-variable transmission portion 11 and step-variable transmission portion 20 fails to be normally operable, to change speed ratio of the other transmission portion such that overall speed ratio ?T of the transmission mechanism 10 determined by the speed ratio ?0 of the continuously-variable transmission portion 11 and speed ratio ? of the step-variable transmission portion 20 is made equal to a value immediate before the above-indicated one transmission portion fails to be normally operable, so that a change of the overall speed ratio ?T is reduced, whereby the vehicle can be run with high drivability.Type: GrantFiled: January 3, 2006Date of Patent: June 9, 2009Assignee: Toyota Jidosha Kabushiki KaishaInventors: Atsushi Tabata, Yutaka Taga
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Patent number: 7534190Abstract: Upon shifting control of differential mechanism 10, speed ratio ?0 of continuously-variable transmission portion 11 and speed ratio ? of automatic transmission portion 20 are determined by vehicle-output control device 82 on the basis of target engine output PE* and vehicle speed V, so as to establish an operating point of engine 8 which provides the target engine output PE* and which follows an optimum-fuel-economy curve, and the shifting control of the continuously-variable transmission portion 11 and the shifting control of the automatic transmission portion 20 are effected substantially concurrently, so that engine speed NE continuously changes, and the differential mechanism 10 is shifted with a reduced shifting shock. Further, the speed ratio ?0 of the continuously-variable transmission portion 11, in other words, the engine speed NE is changed by using first electric motor M1 and/or second electric motor M2, permitting an improvement in shifting response of the differential mechanism 10.Type: GrantFiled: January 3, 2006Date of Patent: May 19, 2009Assignee: Toyota Jidosha Kabuhsiki KaishaInventors: Atsushi Tabata, Yutaka Taga
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Publication number: 20090118955Abstract: A vehicular drive system switchable between a continuously-variable and step-variable shifting states, and a control device for controlling the vehicular drive system so as to reduce a shifting shock of an automatic transmission included in the drive system, which takes place due to an overlap control involving a switching control of the drive system and a shifting control of the automatic transmission.Type: ApplicationFiled: February 23, 2005Publication date: May 7, 2009Inventors: Atsushi Tabata, Yutaka Taga
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Publication number: 20090098969Abstract: A miniaturized vehicular drive apparatus is provided with a reduced size in an axial direction without increasing the number of parallel shafts. A first electric motor M1 and a power distributing mechanism (differential portion) 16 are disposed on a first axis CL1, forming a rotational axis of an input rotary member 14, in series starting therefrom and an automatic transmission (transmission portion) 20 is disposed on a second axis CL2 parallel to the first axis CL1. A drive linkage 23 is provided between a power transmitting member 18, acting as a rotary member placed on the first axis CL1 at an end portion thereof in opposition to the input rotary member 14, i.e., in opposition to an engine 8, and a first intermediate shaft (rotary member) 40, disposed on the second axis CL2 at an end portion thereof in opposition to the input rotary member 14, for power transmitting capability. Thus, a power transmitting path is formed in a C-shape, i.e.Type: ApplicationFiled: June 26, 2006Publication date: April 16, 2009Applicant: Toyota Jidosha Kabushiki KaishaInventors: Atsushi Tabata, Terufumi Miyazaki, Atsushi Kamada, Yutaka Taga
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Patent number: 7513847Abstract: Hybrid controller 52 for a vehicular drive system is operable during a shifting control of step-variable transmission portion 20 for a stepping change of its speed ratio, for changing a speed ratio of continuously-variable transmission portion 11, such that total speed ratio ?T of transmission mechanism 10 defined by the speed ratio of the continuously-variable transmission portion 11 and the speed ratio of the step-variable transmission portion 20 is continuously changed, irrespective of the stepping change of the speed ratio of the step-variable transmission portion 20, so that an amount of stepping change of engine speed NE before and after a shifting action of the step-variable transmission portion 20 is reduced, and a shifting shock of the step-variable transmission portion 20 is reduced. The hybrid controller 52 permits the transmission mechanism 10 to function as a continuously variable transmission, thereby improving fuel economy of the vehicular drive system.Type: GrantFiled: September 17, 2007Date of Patent: April 7, 2009Assignee: Toyota Jidosha Kabushiki KaishaInventors: Atsushi Tabata, Yutaka Taga
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Publication number: 20090082151Abstract: A vehicular drive system including a first electric motor, a power distributing mechanism, and a second electric motor disposed on a first axis, and an automatic transmission portion disposed on a second axis parallel to the first axis, and a power transmitting member at an end of the first axis remote from an input rotary member and a rotary member at an end of the second axis remote from the input rotary member are connected to each other through a drive linkage, thereby a total axial dimension of the first electric motor, power distributing mechanism, and second electric motor and an axial dimension of the automatic transmission portion are substantially equal to each other, whereby the axial dimension of the drive system is reduced. A housing of the vehicular drive system includes mutually separate first, second, third, and fourth casing portions, so the drive system can be easily assembled.Type: ApplicationFiled: June 26, 2006Publication date: March 26, 2009Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Atsushi Tabata, Terufumi Miyazaki, Atsushi Kamada, Yutaka Taga
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Publication number: 20090076694Abstract: A control apparatus for a vehicular drive system arranged to electrically transmit a portion of an output force of an engine through an electric path, which control apparatus is configured to reduce loads of components associated with the electric path and to restrict a temperature rise of the components associated with the electric path, making it possible to reduce the required size of a cooling system.Type: ApplicationFiled: June 14, 2006Publication date: March 19, 2009Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Atsushi Tabata, Yutaka Taga, Yuji Inoue, Atsushi Kamada
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Publication number: 20090075774Abstract: Vehicular drive system which is small-sized and/or improved in its fuel economy. A power distributing mechanism 16, which is provided with a differential-state switching device in the form of a switching clutch C0 and a switching brake B0, is switchable by the switching device between a differential state (continuously-variable shifting state) in which the mechanism is operable as an electrically controlled continuously variable transmission, and a fixed-speed-ratio shifting state in which the mechanism is operable as a transmission having a fixed speed ratio or ratios. The power distributing mechanism 16 is placed in the fixed-speed-ratio shifting state during a high-speed running of the vehicle or a high-speed operation of engine 8, so that the output of the engine 8 is transmitted to drive wheels 38 primarily through a mechanical power transmitting path, whereby fuel economy of the vehicle is improved owing to reduction of a loss of conversion of a mechanical energy into an electric energy.Type: ApplicationFiled: November 12, 2008Publication date: March 19, 2009Inventors: Atsushi TABATA, Yutaka Taga
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Publication number: 20090069965Abstract: Vehicular drive system which is small-sized and/or improved in its fuel economy. A power distributing mechanism 16, which is provided with a differential-state switching device in the form of a switching clutch C0 and a switching brake B0, is switchable by the switching device between a differential state (continuously-variable shifting state) in which the mechanism is operable as an electrically controlled continuously variable transmission, and a fixed-speed-ratio shifting state in which the mechanism is operable as a transmission having a fixed speed ratio or ratios. The power distributing mechanism 16 is placed in the fixed-speed-ratio shifting state during a high-speed running of the vehicle or a high-speed operation of engine 8, so that the output of the engine 8 is transmitted to drive wheels 38 primarily through a mechanical power transmitting path, whereby fuel economy of the vehicle is improved owing to reduction of a loss of conversion of a mechanical energy into an electric energy.Type: ApplicationFiled: November 12, 2008Publication date: March 12, 2009Inventors: Atsushi TABATA, Yutaka Taga
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Publication number: 20090069966Abstract: Vehicular drive system which is small-sized and/or improved in its fuel economy. A power distributing mechanism 16, which is provided with a differential-state switching device in the form of a switching clutch C0 and a switching brake B0, is switchable by the switching device between a differential state (continuously-variable shifting state) in which the mechanism is operable as an electrically controlled continuously variable transmission, and a fixed-speed-ratio shifting state in which the mechanism is operable as a transmission having a fixed speed ratio or ratios. The power distributing mechanism 16 is placed in the fixed-speed-ratio shifting state during a high-speed running of the vehicle or a high-speed operation of engine 8, so that the output of the engine 8 is transmitted to drive wheels 38 primarily through a mechanical power transmitting path, whereby fuel economy of the vehicle is improved owing to reduction of a loss of conversion of a mechanical energy into an electric energy.Type: ApplicationFiled: November 12, 2008Publication date: March 12, 2009Inventors: Atsushi TABATA, Yutaka Taga
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Publication number: 20090029824Abstract: A drive apparatus for vehicle, available to be minimized, is provided. A first planetary gear set (differential device) 24 through which an output of a drive power source is distributed to a first electric motor M1 and a transmitting member 18, and a switching clutch C0 and a switching brake B0 operative to selectively place the first planetary gear set 24 in a differential state to function as an electrically continuously variable transmission and a locked state, are disposed between the first electric motor M1 and a second electric motor M2. This enables a power transmitting state to be performed in a broad range. Additionally, as the first planetary gear set 24 is placed in the locked state under a high output region of an engine to transfer the engine output to drive wheels mainly through a mechanical power transmitting path, an electrical reaction force to be guaranteed with the first electric motor M1 can be reduced, enabling the first electric motor M1 to be minimized.Type: ApplicationFiled: September 27, 2005Publication date: January 29, 2009Inventors: Atsushi Tabata, Yutaka Taga, Terufumi Miyazaki
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Patent number: 7481737Abstract: A control apparatus for a vehicular drive system including a first transmission portion having a differential mechanism operable to distribute an engine output to a first electric motor and a power transmitting member, and a second electric motor disposed in a power transmitting path between the power transmitting member and a drive wheel; and a second transmission portion constituting a part of the power transmitting path.Type: GrantFiled: June 21, 2006Date of Patent: January 27, 2009Assignee: Toyota Jidosha Kabushiki KaishaInventors: Atsushi Tabata, Yutaka Taga, Yuji Inoue, Atsushi Kamada
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Patent number: 7445578Abstract: A control device for a vehicular drive system including (a) a differential portion having a differential mechanism operable to distribute an output of an engine to a first electric motor and a power transmitting member, and a second electric motor disposed in a power transmitting path between the power transmitting member and a drive wheel of a vehicle, (b) a transmission portion which constitutes a part of the power transmitting path, (c) a coupling device operable to place a power transmitting path between the engine and the drive wheel, selectively in a power-transmitting state or a power-cutoff state, and (d) a shift lever operable between a drive position for the coupling device to select the power-transmitting state, and a non-drive position for the coupling device to select the power-cutoff state, the control device including an engine-speed control device for controlling engine speed NE so as not to exceed a predetermined engine speed value NE? while the shift lever is placed in the non-drive positionType: GrantFiled: January 3, 2006Date of Patent: November 4, 2008Assignee: Toyota Jidosha Kabushiki KaishaInventors: Atsushi Tabata, Yutaka Taga
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Publication number: 20080254935Abstract: When a sub transmission mechanism is switched to the LO-side gear stage, a hybrid control unit executes a control operation such that vehicle speed does not exceed limit vehicle speed determined in advance in accordance with the transmission gear ratio of LO-side gear stage. Specifically, the hybrid control unit reduces at least one of the driving torque generated by the engine and the second motor generator, so that rotation speed of the second motor generator does not exceed tolerable rotation speed. Further, the hybrid control unit reduces at least one of the driving torque generated by the engine and the second motor generator when any of temperatures respectively detected by temperature sensors exceed corresponding upper limit temperatures.Type: ApplicationFiled: April 10, 2008Publication date: October 16, 2008Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, AISIN AW CO., LTD.Inventors: Shinji Kasuga, Yutaka Taga, Daiki Suyama, Yoshiyuki Onozawa
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Patent number: 7426972Abstract: A control device for a vehicular drive system including (a) a differential mechanism operable to distribute an output of an engine (8) to a first electric motor and a power transmitting member, (b) a second electric motor disposed in a power transmitting path between the power transmitting member and a drive wheel of a vehicle, and (c) a differential-state switching device operable to place the differential mechanism selectively in one of a differential state in which the differential mechanism is operable to perform a differential function and a locked state in which the differential mechanism is not operable to perform the differential function, the control device including an engine-stop switching control portion operable to control the differential-state switching device to place the differential mechanism in the differential state, upon stopping of the engine, so that the engine speed can be rapidly lowered to zero by controlling the first electric motor in the differential state of the differential mechType: GrantFiled: July 5, 2005Date of Patent: September 23, 2008Assignee: Toyota Jidosha Kabushiki KaishaInventors: Atsushi Tabata, Yutaka Taga
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Publication number: 20080200303Abstract: Hybrid controller 52 for a vehicular drive system is operable during a shifting control of step-variable transmission portion 20 for a stepping change of its speed ratio, for changing a speed ratio of continuously-variable transmission portion 11, such that total speed ratio ?T of transmission mechanism 10 defined by the speed ratio of the continuously-variable transmission portion 11 and the speed ratio of the step-variable transmission portion 20 is continuously changed, irrespective of the stepping change of the speed ratio of the step-variable transmission portion 20, so that an amount of stepping change of engine speed NE before and after a shifting action of the step-variable transmission portion 20 is reduced, and a shifting shock of the step-variable transmission portion 20 is reduced. The hybrid controller 52 permits the transmission mechanism 10 to function as a continuously variable transmission, thereby improving fuel economy of the vehicular drive system.Type: ApplicationFiled: September 17, 2007Publication date: August 21, 2008Inventors: Atsushi Tabata, Yutaka Taga
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Patent number: 7396316Abstract: Hybrid controller 52 for a vehicular drive system is operable during a shifting control of step-variable transmission portion 20 for a stepping change of its speed ratio, for changing a speed ratio of continuously-variable transmission portion 11, such that total speed ratio ?T of transmission mechanism 10 defined by the speed ratio of the continuously-variable transmission portion 11 and the speed ratio of the step-variable transmission portion 20 is continuously changed, irrespective of the stepping change of the speed ratio of the step-variable transmission portion 20, so that an amount of stepping change of engine speed NE before and after a shifting action of the step-variable transmission portion 20 is reduced, and a shifting shock of the step-variable transmission portion 20 is reduced. The hybrid controller 52 permits the transmission mechanism 10 to function as a continuously variable transmission, thereby improving fuel economy of the vehicular drive system.Type: GrantFiled: March 30, 2005Date of Patent: July 8, 2008Assignee: Toyota Jidosha Kabushiki KaishaInventors: Atsushi Tabata, Yutaka Taga
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Publication number: 20080076623Abstract: Vehicle-starting-engine-torque restricting means 86 is provided to restrict engine torque TE upon starting of a vehicle with engine 8 used as a vehicle drive power source, so that a required output of first electric motor M1 which generates a reaction force corresponding to the engine torque TE can be made smaller than in the case where the engine torque TE is not restricted. Namely, the vehicle-starting-engine-torque restricting means 86 eliminates a need of increasing the maximum output of the first electric motor M1 to generate the reaction force corresponding to the engine torque TE, making it possible to reduce the required size of the first electric motor M1.Type: ApplicationFiled: October 27, 2005Publication date: March 27, 2008Inventors: Atsushi Tabata, Yutaka Taga, Atsushi Kamada
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Patent number: 7322902Abstract: A control device for a vehicular drive system including a differential mechanism operable to distribute an output of an engine to a first electric motor and a power transmitting member, and a second electric motor disposed in a power transmitting path between the power transmitting member and a drive wheel of a vehicle. The control device includes a differential-state switching device operable to place the differential mechanism selectively in one of a differential state and a non-differential state, and a switching control device operable to control the differential-state switching device, so as to place the differential mechanism in the differential state when the vehicle is in a motor-drive mode in which at least one of the first and second electric motors is used as a drive power source to drive the vehicle.Type: GrantFiled: May 5, 2005Date of Patent: January 29, 2008Assignee: Toyota Jidosha Kabushiki KaishaInventors: Atsushi Tabata, Yutaka Taga