Patents by Inventor Seiji Kuwahara
Seiji Kuwahara 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: 20150336570Abstract: Control device of hybrid vehicle including an engine connected via a clutch to power transmission path and a rotator acting at least as an electric motor, hybrid vehicle being configured to execute an engine running mode in which clutch is engaged to use at least engine as a drive force source for running and a motor running mode in which clutch is released to use rotator as drive force source for running, control device putting clutch into slip engagement to crank and start engine before clutch is completely engaged at time of switching to engine running mode during stop of engine with clutch released, control device of hybrid vehicle, when clutch temperature reaches predefined value at time of switching to the engine running mode, releasing clutch and causing rotator to generate drive force for running while controlling rotation speed of engine to synchronize rotation speeds before and after clutch.Type: ApplicationFiled: December 26, 2012Publication date: November 26, 2015Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Toshio SUGIMURA, Seiji KUWAHARA, Takahiko TSUTSUMI, Koki MINAMIKAWA, Shun SATO
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Publication number: 20150329106Abstract: A control device of a hybrid vehicle includes: an engine; a first electric motor; a second electric motor coupled to a drive shaft of the engine; a clutch disposed in a power transmission path between the engine and the first electric motor; an electric oil pump generating an oil pressure by electric power; a mechanical oil pump included in a power transmission path closer to the first electric motor relative to the clutch, the mechanical oil pump generating an oil pressure by a drive force of at least one of the engine and the first electric motor; and an electric storage device giving/receiving electric power to/from the second electric motor and supplying electric power to the electric oil pump. When an open failure occurs in the clutch, the second electric motor generates electricity by driving the engine and an oil amount supplied from the electric oil pump is larger than an oil amount supplied from the mechanical oil pump.Type: ApplicationFiled: December 12, 2012Publication date: November 19, 2015Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Seiji KUWAHARA, Toshio SUGIMURA, Takahiko TSUTSUMI, Koki MINAMIKAWA, Shun SATO
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Patent number: 9180876Abstract: Embodiments described herein relate to control apparatuses for hybrid vehicles which permit starting the engine and a shift-down action of the transmission while assuring not only a reduction of the heat generated by a clutch, but also an improvement in the response of the vehicle to an operator's desire for high drivability. In one embodiment, the control apparatus controls the hybrid vehicle such that when the transmission is required to be shifted down while the hybrid vehicle is switched from a motor drive mode to an engine drive mode, a time of initiation of the shift-down action of the transmission is delayed by a longer length of time when a temperature of the clutch upon initiation of an engine starting control to start the engine is relatively high than when the temperature is relatively low. Various other embodiments of control apparatuses for hybrid vehicles are also described.Type: GrantFiled: February 4, 2014Date of Patent: November 10, 2015Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Takahiko Tsutsumi, Toshio Sugimura, Seiji Kuwahara, Shun Sato, Koki Minamikawa
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Patent number: 9151381Abstract: One control mode is selected from a plurality of control modes each setting a target value of a primary pulley revolution speed NIN and prioritized in a predetermined order. When the control mode is changed, the target value of the primary pulley revolution speed NIN is set so as to vary from the target value set in the control mode before change to the target value set in the control mode after change in accordance with the control mode that is higher in priority among the control modes before and after change. A continuously variable transmission is controlled such that the primary pulley revolution speed NIN reaches the set target value.Type: GrantFiled: March 15, 2010Date of Patent: October 6, 2015Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Daisuke Inoue, Akihide Ito, Seiji Kuwahara, Shinya Toyoda, Motonori Kimura
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Publication number: 20150136253Abstract: A hydraulic control circuit for a drive line includes first and second switching valves and first and second solenoid valves. Each switching valve is alternatively switched by a switching hydraulic pressure to connect any two of three ports. The first port of the first switching valve is connected to a hydraulic actuator. The first port of the second switching valve is connected to the second port of the first switching valve. The first solenoid valve supplies the switching hydraulic pressure to the switching valves. The second solenoid valve regulates a control hydraulic pressure supplied to the hydraulic actuator. Any one of three oil paths is communicated with the hydraulic actuator by supplying the control hydraulic pressure via the third port of the first switching valve or the second or third port of the second switching valve and supplying the switching hydraulic pressure to at least one switching valve.Type: ApplicationFiled: November 18, 2014Publication date: May 21, 2015Inventors: Seiji Kuwahara, Toshio Sugimura, Takahiko Tsutsumi, Masato Yoshikawa, Koki Minamikawa, Naoki Nakanishi
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Patent number: 9022899Abstract: Control apparatus for hybrid vehicles are described which reduce the heat generated by a clutch and improve the response of the hybrid vehicle when an operator requests a high degree of acceleration while starting the engine and the transmission is required to perform a shift-down. In one embodiment, when the engine is required to start while the transmission is required to perform a shift-down action, the control apparatus holds a hydraulic pressure of a releasing side clutch of the transmission at a predetermined lowest stand-by value preventing a slipping action of the releasing side clutch, while a clutch K0 between the motor and engine is placed in a slipping state, and reduces the hydraulic pressure of the releasing side clutch from the lowest stand-by value in the slipping state of the clutch K0 after the clutch K0 is placed in the fully engaged state.Type: GrantFiled: February 4, 2014Date of Patent: May 5, 2015Assignee: Toyota Jidosha Kabushiki KaishaInventors: Takahiko Tsutsumi, Toshio Sugimura, Seiji Kuwahara, Koki Minamikawa, Shun Sato
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Publication number: 20150120154Abstract: A speed change control system for reducing shift shocks of clutch-to-clutch shifting is provided. The control system is applied to a vehicle in which a transmission having a plurality of engagement devices is connected to an output side of a prime mover, and in which a gear stage of the transmission is shifted among a plurality of stages by changing engagement states of the engagement devices. The speed change control system is configured to carry out a clutch-to-clutch shifting of the gear stage from a predetermined gear stage to another gear stage by gradually reducing a torque capacity of the predetermined engagement device to be disengaged while gradually increasing a torque capacity of another engagement device to be engaged.Type: ApplicationFiled: May 8, 2012Publication date: April 30, 2015Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Seiji Masunaga, Yoshio Hasefawa, Seiji Kuwahara, Nobufusa Kobayashi
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Publication number: 20150120155Abstract: A speed change control system for reducing shift shocks of clutch-to-clutch shifting is provided. The control system is applied to a vehicle in which a transmission having engagement devices is connected to an output side of a prime mover, and in which a gear stage of the transmission is shifted among a plurality of stages by changing engagement states of the engagement devices. The speed change control system carries out a clutch-to-clutch shifting from a predetermined gear stage to another gear stage by reducing a torque capacity of the predetermined engagement device to be disengaged while increasing a torque capacity of another engagement device to be engaged.Type: ApplicationFiled: May 8, 2012Publication date: April 30, 2015Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Seiji Masunaga, Yoshio Hasegawa, Seiji Kuwahara, Nobufusa Kobayashi
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Patent number: 8935063Abstract: A dynamic threshold value when an engine, an automatic transmission and the like are in a transition state is calculated in accordance with a static threshold value determined based on a state where the engine, the automatic transmission and the like are stabilized. The engine and the automatic transmission are controlled in accordance with a result of comparison between target drive force or target engine torque and the dynamic threshold value.Type: GrantFiled: January 29, 2009Date of Patent: January 13, 2015Assignee: Toyota Jidosha Kabushiki KaishaInventors: Seiji Kuwahara, Toshiya Oishi
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Publication number: 20140221152Abstract: Embodiments of control apparatus for hybrid vehicles are described which reduce the heat generated by a clutch and improve the response of the hybrid vehicle when an operator requests a high degree of acceleration while starting the engine and the transmission is required to perform a shift-down. In one embodiment, when the engine is required to start while the transmission is required to perform a shift-down action, the control apparatus holds a hydraulic pressure of a releasing side clutch of the transmission at a predetermined lowest stand-by value preventing a slipping action of the releasing side clutch, while a clutch K0 between the motor and engine is placed in a slipping state, and reduces the hydraulic pressure of the releasing side clutch from the lowest stand-by value in the slipping state of the clutch K0 after the clutch K0 is placed in the fully engaged state.Type: ApplicationFiled: February 4, 2014Publication date: August 7, 2014Applicant: Toyota Jidosha Kabushiki KaishaInventors: Takahiko Tsutsumi, Toshio Sugimura, Seiji Kuwahara, Koki Minamikawa, Shun Sato
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Publication number: 20140221156Abstract: A control device for a vehicle that includes an engine, a motor, and a clutch provided in a power transmission path between the engine and the motor. The control device includes an ECU. The ECU is configured to switch travel states of the vehicle from a first to a second travel state. In the first travel state, the vehicle travels by using driving force generated by at least the engine while the clutch is engaged. In the second travel state, the vehicle travels by using driving force generated by the motor while the engine is stopped and the clutch is disengaged. The ECU is configured to maintain an operation of the engine and keep the clutch engaged after target driving force of the engine changes to a negative value when disengagement of the clutch is prohibited in switching from the first travel state to the second travel state.Type: ApplicationFiled: January 31, 2014Publication date: August 7, 2014Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Toshio SUGIMURA, Seiji KUWAHARA, Takahiko TSUTSUMI, Koki MINAMIKAWA, Shun SATO
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Publication number: 20140222270Abstract: The embodiments described herein relate to control apparatuses for hybrid vehicles which permit starting of an engine and a shift-down action of a transmission, while assuring a reduction of heat generated by a clutch and an improvement of a response of the hybrid vehicle to a vehicle operator's desire for high drivability. In one embodiment, the control apparatus controls the hybrid vehicle such that, when the transmission is required to be shifted down while the hybrid vehicle is switched from the motor drive mode to the engine drive mode, a rate of change of the input speed of said transmission is lower than when only the shift-down action is required to be performed, such that the rate of change of the input speed is relatively low when the input speed of the transmission to be established upon completion of the shift-down action is relatively high.Type: ApplicationFiled: February 4, 2014Publication date: August 7, 2014Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Takahiko Tsutsumi, Toshio Sugimura, Seiji Kuwahara, Koki Minamikawa, Shun Sato
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Publication number: 20140222269Abstract: Embodiments described herein relate to control apparatuses for hybrid vehicles which permit starting the engine and a shift-down action of the transmission while assuring not only a reduction of the heat generated by a clutch, but also an improvement in the response of the vehicle to an operator's desire for high drivability. In one embodiment, the control apparatus controls the hybrid vehicle such that when the transmission is required to be shifted down while the hybrid vehicle is switched from a motor drive mode to an engine drive mode, a time of initiation of the shift-down action of the transmission is delayed by a longer length of time when a temperature of the clutch upon initiation of an engine starting control to start the engine is relatively high than when the temperature is relatively low. Various other embodiments of control apparatuses for hybrid vehicles are also described.Type: ApplicationFiled: February 4, 2014Publication date: August 7, 2014Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Takahiko Tsutsumi, Toshio Sugimura, Seiji Kuwahara, Shun Sato, Koki Minamikawa
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Publication number: 20140148985Abstract: A control system for a hybrid vehicle includes a controller. When a downshift of a transmission and an increase in an amount of regeneration are carried out during regenerative coast traveling in which regeneration is carried out by an electric motor, and when a state of charge of a battery is lower than a predetermined value, the controller increases the amount of regeneration before completion of the downshift. When the state of charge of the battery is higher than or equal to the predetermined value, the controller increases the amount of regeneration after completion of the downshift.Type: ApplicationFiled: November 21, 2013Publication date: May 29, 2014Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Shun SATO, Toshio SUGIMURA, Seiji KUWAHARA, Takahiko TSUTSUMI, Koki MINAMIKAWA
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Patent number: 8738253Abstract: An ECU controls an automatic transmission that can be manually shifted. The ECU executes a program that includes i) the step of, when there are a plurality of allowed gears that are allowed at the time of a downshift operation, continuously determining whether the engine speed NE after a downshift will be in a preset overspeed region for each allowed gear when the second and subsequent allowed gears are lower than an output gear, and when there is an allowed gear that will result in the engine speed NE being in the overspeed region, ii) the step of cancelling that allowed gear. Thus this control appropriately suppresses overspeeding of the engine while executing a manual shift in response to an operation by the driver without bothering the driver.Type: GrantFiled: December 18, 2008Date of Patent: May 27, 2014Assignee: Toyota Jidosha Kabushiki KaishaInventors: Ichiro Kitaori, Hiroyuki Sawada, Yoshio Hasegawa, Kazuyuki Shiiba, Toshihiro Fukumasu, Nobufusa Kobayashi, Seiji Kuwahara
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Patent number: 8630775Abstract: When an automatic transmission is in a manual mode, a transmission ECU calculates a speed sftrng manually requested by the driver and a speed sftrngmap set by a shift map and then performs a shift prohibition procedure. In this procedure, if the engine coolant temperature is equal to or lower than a predetermined coolant temperature or the AT fluid temperature is equal to or lower than a predetermined fluid temperature, a prohibition, determination flag xthlow is set to “on”, and if the engine coolant temperature is higher than the predetermined coolant temperature and the AT fluid temperature is higher than the predetermined fluid temperature, the prohibition determination flag xthlow is set to “off”. When the prohibitions determination flag xthlow is “on”, the speed sftrngmap is set as the upper limit of the speed sftrng.Type: GrantFiled: September 23, 2008Date of Patent: January 14, 2014Assignee: Toyota Jidosha Kabushiki KaishaInventors: Ichiro Kitaori, Seiji Kuwahara, Hiroyuki Sawada, Kazuyuki Shiiba, Toshihiro Fukumasu
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Patent number: 8589051Abstract: An ECU includes: an engine control unit that controls devices provided for an engine on the basis of a target engine rotational speed; and an engine model that calculates the target engine rotational speed such that the target engine rotational speed varies in accordance with a target engine torque and an actual engine rotational speed in a steady state, and that calculates the target engine rotational speed such that the target engine rotational speed varies in accordance with the target engine torque independently of the actual engine rotational speed in a transient state in which the engine is unstable as compared with the steady state. When the engine is controlled by the thus configured ECU, the control accuracy is improved.Type: GrantFiled: December 23, 2008Date of Patent: November 19, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventors: Seiji Kuwahara, Masato Kaigawa, Toshiya Oishi, Shogo Matsumoto
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Patent number: 8504264Abstract: A target gear ratio calculation unit calculates a target gear ratio TGR of a transmission. A setting unit sets a target gear TG according to target gear ratio TGR. A multi-speed transmission control unit controls the transmission according to target gear TG. A target driving force calculation unit calculates target driving force TF of a vehicle. A correction unit corrects target driving force TF according to a gear ratio of the transmission. A conversion unit converts target driving force TF into target engine torque TTE. An engine control unit controls an engine according to target engine torque TTE. Modules used for the engine control unit, the target driving force calculation unit, the conversion unit, and the target gear ratio calculation unit are used in common in a case where the transmission is a multi-speed transmission and in a case where the transmission is a continuously variable transmission.Type: GrantFiled: November 12, 2008Date of Patent: August 6, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventors: Seiji Kuwahara, Toshiya Oishi
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Patent number: 8409056Abstract: A shift output torque control unit executes a shift output torque control to control an engine torque so as to reduce a driving force difference, which is a variation width of a driving force due to downshift of an automatic transmission. Thus, in comparison with the case in which the shift output torque control is not executed, it is possible to smooth a variation in driving force associated with the downshift. As a result, occupants' comfort and controllability to driving operation may be improved.Type: GrantFiled: November 6, 2008Date of Patent: April 2, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventors: Seiji Kuwahara, Hideaki Otsubo, Masato Kaigawa, Shogo Matsumoto, Masayuki Baba
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Patent number: 8313414Abstract: An electronic control unit is provided with two types of gear change maps: a first gear change map based on the vehicle speed and the accelerator pedal operation amount; and a second gear change map based on the vehicle speed and the required drive force of the vehicle. The electronic control unit determines whether the automatic transmission should downshift with reference to the first gear change map, and determines whether the automatic transmission should upshift with reference to the second gear change map.Type: GrantFiled: October 21, 2008Date of Patent: November 20, 2012Assignee: Toyota Jidosha Kabushiki KaishaInventors: Seiji Kuwahara, Hideaki Otsubo, Masato Kaigawa, Masayuki Baba