Control Responsive To Fluid Drive Patents (Class 477/61)
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Patent number: 10670088Abstract: A hydraulic clutch device includes a pressure regulating valve located on a downstream side in an oil flowing direction, a casing housing the hydraulic clutch, an insertion hole holding at least a part of the pressure regulating valve, an upstream side oil passage having an opening part introducing the oil from the hydraulic clutch into the insertion hole, and a downstream side oil passage having another opening part discharge the oil from the other opening part to the downstream side of the insertion hole. A position of a first virtual line (L1) which passes through the center-of-gravity point of a cross section of the opening part of the upstream side oil passage and a position of a second virtual line (L2) which passes through the center-of-gravity point of a cross section of the insertion hole are arranged so as to be different from each other.Type: GrantFiled: March 8, 2018Date of Patent: June 2, 2020Assignee: HONDA MOTOR CO., LTD.Inventors: Nobutaka Yamaguchi, Kenji Niwata
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Patent number: 10106148Abstract: A vehicle includes an engine having a crankshaft, a transmission, an electric machine, and at least one controller. The transmission includes a torque converter having a turbine fixed to a turbine shaft that is driveably connected to driven wheels of the vehicle. The torque converter includes an impeller and a bypass clutch configured to selectively lock the impeller and the turbine relative to each other. The electric machine includes a rotor selectively coupled to the crankshaft via a disconnect clutch and fixed to the impeller. The at least one controller is configured to generate a first torque command for the electric machine that defines a magnitude equal to driver-demanded torque while the bypass clutch is locked. The controller is further configured to, in response to a reduction in fluid pressure supplied to the bypass clutch, generate a second torque command for the electric machine that defines a magnitude equal to driver-demanded torque plus impeller inertia torque.Type: GrantFiled: August 19, 2016Date of Patent: October 23, 2018Assignee: Ford Global Technologies, LLCInventors: Jason Meyer, Rajit Johri, Mark Steven Yamazaki, Bernard D. Nefcy, Jeffrey Allen Doering, Scott James Thompson, Daniel Scott Colvin, Scott Steadmon Thompson
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Patent number: 9238459Abstract: A battery charging method for a hybrid electric vehicle, may include a step of receiving a vehicle gradient value through a transmission control unit (TCU) or an inclination sensor when the vehicle stops, a step of converting a transmission stage into an N stage and driving an engine to recharge a battery by a main motor when the received vehicle gradient value a preset gradient value or less, and a step of charging the battery by Generating the main motor by engaging an engine clutch after the engine driven.Type: GrantFiled: October 25, 2012Date of Patent: January 19, 2016Assignees: Hyundai Motor Company, Kia Motor CorporationInventors: Gwang Seob Shin, Yeon Ho Kim
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Patent number: 9206897Abstract: The present invention provides a method for setting a shift point for shifting a transmission for a powered vehicle between a first gear ratio and a second gear ratio. The method includes determining input power data points based on real-time input torque data. The input torque data includes a maximum input torque. The method also includes calculating a gear step value based on the first gear ratio and second gear ratio. The method further includes determining a first power value and computing a second power value based on the gear step value. The first power value and second power value are compared to one another and adjustments are incrementally made in the first power value speed until the difference between first and second power values meets a threshold. The shift point is therefore based on the result of comparing the first power value and the second power value and the corresponding speed associated with the first power value.Type: GrantFiled: April 29, 2014Date of Patent: December 8, 2015Assignee: Allison Transmission, Inc.Inventor: Edmond M. Etchason
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Patent number: 9097337Abstract: A method for controlling hydraulic line pressure of a hydraulic control system in transmission includes determining an available flow from a plurality of hydraulic pumps, determining a flow consumption of functions served by the hydraulic control system, determining an estimated hydraulic line pressure based upon the flow from the pumps and the flow consumption, determining a desired hydraulic line pressure, and controlling the hydraulic pumps based upon the desired hydraulic line pressure and the estimated hydraulic line pressure.Type: GrantFiled: October 10, 2008Date of Patent: August 4, 2015Assignees: GM Global Technology Operations LLC, Daimler AG, Chrysler Group LLC, Bayerische Motoren Werke AktiengesellschaftInventors: Jy-Jen F. Sah, Ali K Naqvi
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Patent number: 9033852Abstract: In hydraulic control, an electronic control unit controls controlled hydraulic pressure of a control valve in order to control a hydraulic oil amount in a torque converter and a hydraulic oil pressure of a forward-reverse travel switching mechanism, and the electronic control unit increases the controlled hydraulic pressure when the hydraulic oil amount in the torque converter is insufficient at an engine start or immediately after the engine start in comparison with a case where the hydraulic oil amount in the torque converter is sufficient. The hydraulic control device includes: the torque converter; the forward-reverse travel switching mechanism; the control valve configured to change the hydraulic oil amount in the torque converter and the hydraulic oil pressure of the forward-reverse travel switching mechanism by changing the single controlled hydraulic pressure; and electronic control unit.Type: GrantFiled: April 2, 2014Date of Patent: May 19, 2015Assignee: Toyota Jidosha Kabushiki KaishaInventors: Kenta Horiike, Kei Yuasa, Sei Kojima, Hiromitsu Nitani
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Patent number: 9014934Abstract: A method of controlling a pump for a hybrid transmission includes commanding a first line pressure of the transmission and deriving a first torque value—an open-loop torque value—from the first line pressure command, and commanding the pump to operate at the first torque value. The method monitors actual speed of the pump and derives a second torque value—a closed-loop torque value—therefrom. A third torque value is derived from the first and second torque values, and the pump commanded to operate at the third torque value. A first speed value may be derived from the first line pressure command, and the second torque value derived from the difference between the monitored and the first speed values. Deriving the third torque value may include a substantially-linear combination of the first and second torque values.Type: GrantFiled: May 19, 2009Date of Patent: April 21, 2015Assignee: GM Global Technology Operations LLCInventor: Jy-Jen F. Sah
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Patent number: 8700247Abstract: A hybrid powertrain includes an engine, an electric machine, and a transmission. A method to control the powertrain includes monitoring operation of the powertrain, determining whether conditions necessary for growl to occur excluding motor torque and engine torque are present, and if the conditions are present controlling the powertrain based upon avoiding a powertrain operating region wherein the growl is enabled.Type: GrantFiled: December 5, 2012Date of Patent: April 15, 2014Assignee: GM Global Technology Operations LLCInventors: Jeremy Wise, Chihang Lin, Anthony H. Heap
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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: 8560188Abstract: A sport running estimated value LEVELSP obtained by searching a value on a map prepared in advance based on an average values AGYAVE of lateral accelerations GY of a vehicle and on average values of vehicle speed changes is calculated, and a vehicle speed on a shift map is searched based on the sport running estimated value LEVELSP and an estimated value DA of a vehicle gradient, whereby a downshift vehicle speed VA at which a downshift is implemented is calculated. Then, the downshift is implemented in a case where actuation of a brake is detected, deceleration of the vehicle is a predetermined value or more, and a current vehicle speed is a downshift vehicle speed VA or more. In such a way, running on a meandering road, for which the downshift and a subsequent shift hold should be implemented, is sensed appropriately.Type: GrantFiled: January 2, 2013Date of Patent: October 15, 2013Assignee: Honda Motor Co., Ltd.Inventors: Yutaka Ishikawa, Hiroshi Saito, Yasuhiro Gokan
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Patent number: 8475335Abstract: A vehicle includes an engine, torque converter, transmission, accumulator, sensor, and controller. The engine is automatically restarted in response to a start signal during an engine auto-start event. The transmission has a calibrated line pressure and a plurality (n) of clutches. The (n) clutches are engaged to execute the engine auto-start event. The accumulator delivers fluid under pressure to the transmission in response to the start signal. The controller controls (n?1) of the plurality (n) of clutches to the calibrated line pressure in response to detecting the start signal. The controller also modifies clutch fill parameters which control a fill sequence of the remaining clutch, i.e., the designated control clutch, as a function of a deviation of the measured turbine speed from a theoretical no-slip turbine speed. A system includes the transmission, sensor, accumulator, and controller. A method for controlling the designated clutch is also disclosed.Type: GrantFiled: September 21, 2011Date of Patent: July 2, 2013Assignee: GM Global Technology Operations LLCInventors: Ronald F. Lochocki, Jr., Joseph J. Page, Sindu Sebastian
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Patent number: 8317655Abstract: A hydraulic pressure control apparatus for a torque converter includes a relay valve switching levels of a hydraulic pressure in the hydraulic power transmission chamber and establishing selective connections between a cooler and the hydraulic power transmission chamber or between the cooler and a hydraulic pressure supply source of which a flow amount of the operational fluid is regulated by a first orifice, an electronic control unit controlling operations of the relay valve, a hydraulic pressure declination determining portion judging whether the hydraulic pressure of the hydraulic pressure supply source is lower than a threshold value based on a predetermined vehicle state, and a switching command outputting portion outputting a command to connect the cooler and the hydraulic pressure supply source by the relay valve when the hydraulic pressure declination determining portion determines that the hydraulic pressure of the hydraulic pressure supply source is lower than the threshold value.Type: GrantFiled: July 14, 2010Date of Patent: November 27, 2012Assignee: Aisin Seiki Kabushiki KaishaInventor: Osamu Sakamoto
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Patent number: 8152689Abstract: A method of operating a hydraulic pump of a drive train of a motor vehicle having a transmission with a hydrodynamic torque converter and a engine, with the input speed of the hydraulic pump being adjusted depending on the speed of the engine. The input speed of the hydraulic pump is adjusted depending on the pump speed of the torque converter, which corresponds to the speed of the engine and depends on the turbine speed of the torque converter, such that when the pump speed of the torque converter is higher than the turbine speed of the same, the hydraulic pump is operated at a speed higher than the speed of the engine. When the turbine speed of the torque converter and the pump speed of the same equalize, the excessive increase in the input speed of the hydraulic pump is reduced in relation to the speed of the engine.Type: GrantFiled: August 15, 2008Date of Patent: April 10, 2012Assignee: ZF Friedrichshafen AGInventor: Kai Borntrager
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Patent number: 8137238Abstract: A gearshift controller for an industrial vehicle, includes: a speed ratio detection unit that detects a speed ratio of speeds of an input axis and of an output axis of a torque converter; a gearshift control unit that shifts up a speed stage when the detected speed ratio is equal to or more than a first predetermined value and shifts down the speed stage when the detected speed ratio is equal to or less than a second predetermined value, which is smaller than the first predetermined value; and an operation member with which a downshift to the first speed is instructed by operation thereof by an operator. When the downshift is instructed by the operation member, the gearshift control unit controls the speed stage to be kept at the first speed for a predetermined time period regardless of the speed ratio detected by the speed ratio detection unit.Type: GrantFiled: November 30, 2007Date of Patent: March 20, 2012Assignee: Hitachi Construction Machinery Co., Ltd.Inventors: Koji Hyodo, Tetsuji Tanaka, Eiichi Sakai, Genichiro Ishimaru, Tomoo Takahashi, Yasuo Yamazaki
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Patent number: 8095284Abstract: An automatic transmission control unit determines whether or not a constantly open failure, in which a switch valve cannot switch a pressure regulating valve and a second hydraulic chamber to a non-communicative state, has occurred on the basis of a parameter (an inertia phase time, for example) representing a dynamic characteristic during a shift from a first gear position to a second gear position. The determination of the constantly open failure is begun after initial variation in the parameter representing the dynamic characteristic during the shift has been eliminated through learning control in which the dynamic characteristic during the shift is caused to approach a target dynamic characteristic.Type: GrantFiled: June 4, 2009Date of Patent: January 10, 2012Assignee: JATCO LtdInventors: Fumitaka Nagashima, Hajime Tasaka, Yoshihide Shinso
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Publication number: 20110118081Abstract: A hydraulic control system for controlling a transmission includes an accumulator, a plurality of control devices, and a plurality of valves. The accumulator provides pressurized hydraulic fluid to a pressure control subsystem during an engine restart. The plurality of control devices includes solenoids and one way ball check valves. The plurality of valves include compensator feed valves, relay valves, and mode valves.Type: ApplicationFiled: November 13, 2009Publication date: May 19, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Steven P. Moorman, Peter Donald Bock
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Publication number: 20090093339Abstract: A powertrain for a vehicle includes an engine having an output and a transmission selectively driven by the output of the engine. A torque converter is disposed between the engine and the transmission for selectively coupling the output of the engine to the transmission. A controller is in communication with the engine and the torque converter and controls a pressure: within the torque converter based on an input parameter supplied to the engine.Type: ApplicationFiled: October 3, 2007Publication date: April 9, 2009Inventor: Gang Chen
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Patent number: 7513851Abstract: A method and system for regulating engagement of a torque converter clutch (TCC) in a vehicle incorporating a transmission that is driven by an engine through a torque converter includes determining a non-linear slip profile based on vehicle operating parameters, calculating an actual TCC slip, calculating a TCC ramp pressure based on the non-linear slip profile and the actual TCC slip and regulating a TCC engagement pressure based on the TCC ramp pressure.Type: GrantFiled: September 1, 2006Date of Patent: April 7, 2009Assignee: GM Global Technology Operations, Inc.Inventors: Jean Sieffert, Regis Casteran
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Publication number: 20090054206Abstract: A torque converter having a lockup clutch or a coupling device, for selectively providing a mechanical connection between a drive unit and a drive train. The lockup clutch (C) or coupling device has a driving part connected to the drive unit and a driven part connected to the drive train. The torque converter also has a control system for applying a first pressure in a sense to cause frictional engagement between the driving part and the driven part and a second pressure in a sense to cause disengagement of the driving part and the driven part. A differential between the pressures is progressively controllable by the control system so as to control the relative positioning between the driven part and the driving part.Type: ApplicationFiled: August 18, 2005Publication date: February 26, 2009Inventors: Richard Terrence Tamba, Darren Lee Firth
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Publication number: 20090048065Abstract: A method of operating a hydraulic pump of a drive train of a motor vehicle having a transmission with a hydrodynamic torque converter and a engine, with the input speed of the hydraulic pump being adjusted depending on the speed of the engine. The input speed of the hydraulic pump is adjusted depending on the pump speed of the torque converter, which corresponds to the speed of the engine and depends on the turbine speed of the torque converter, such that when the pump speed of the torque converter is higher than the turbine speed of the same, the hydraulic pump is operated at a speed higher than the speed of the engine. When the turbine speed of the torque converter and the pump speed of the same equalize, the excessive increase in the input speed of the hydraulic pump is reduced in relation to the speed of the engine.Type: ApplicationFiled: August 15, 2008Publication date: February 19, 2009Applicant: ZF Friedrichshafen AGInventor: Kai Borntrager
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Patent number: 7338407Abstract: Provided is an apparatus to enable a torque transmitting mechanism within an automatically shiftable power transmission to disengage at vehicle stop such that the slip within a fluid drive device is reduced. When vehicle movement is required a main pressure regulator trims the torque transmitting mechanism into engagement. A method of reducing engine load at vehicle stop by employing the apparatus of the present invention is also provided.Type: GrantFiled: January 17, 2006Date of Patent: March 4, 2008Assignee: General Motors CorporationInventors: Charles F. Long, Jeffrey J. Cole, Phillip F. Mc Cauley
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Patent number: 7090614Abstract: An automatic transmission includes a plurality of frictional engagement elements for constructing plural shift stages with combinations of engagement and disengagement thereof, a control portion for controlling the engagement and the disengagement of the frictional engagement elements, a switching device switching to a learning mode for learning a precharge time, and a precharge time determination device. The precharge time determination device transits the frictional engagement elements to an engagement side by maintaining the hydraulic pressure for determining the precharge time at a first precharge pressure while maintaining input shaft rotational speed at the learning mode at a vehicle stop state. A first precharge time defined from a start of maintaining the first precharge pressure until variation of an input value assumes significant is obtained. And a second precharge time at a second precharge pressure is obtained to be set for learning by a predetermined formula.Type: GrantFiled: July 14, 2004Date of Patent: August 15, 2006Assignee: Aisin Seiki Kabushiki KaishaInventor: Kiyoharu Takagi
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Patent number: 6942597Abstract: An engaging force of a pump impeller (1a) connected to an engine (21) and a turbine runner (1b) connected to an automatic transmission (23) is controlled by a controller (5). The controller (5) determines a target relative rotation speed of the pump impeller (1a) and the turbine runner (1b), and performs feedback control of the engaging force such that the difference between the target relative rotation speed and the real relative rotation speed is decreased. The controller (5) also performs feedforward control of the engaging force in a increasing direction. When the engine (21) is in a predetermined engine-stall prevention condition, the controller (5) prohibits the feedforward control so as to prevent an interference between feedback control and feedforward control.Type: GrantFiled: January 14, 2004Date of Patent: September 13, 2005Assignee: Nissan Motor Co., Ltd.Inventors: Satoshi Segawa, Kazutaka Adachi
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Patent number: 6709363Abstract: A transmission unit is composed of an engine E, a torque converter TC, and an automatic transmission TM. The engine restart and vehicle start control apparatus comprises an electromagnetic valve capable of calculating the pump impeller suction torque of the torque converter and setting the oil pressure increase ratio for the oil pressure supplied to the vehicle start clutch. When the engine is restarted from an engine stopped state and the vehicle start stage is set by supplying hydraulic oil to a friction engagement element and engaging the friction engagement element, an oil pressure supply increasing at a first oil pressure increase ratio is conducted till the calculated pump impeller suction torque reaches the prescribed criterial value, and an oil pressure supply increasing at a second oil pressure increase ratio which is less than the first oil pressure increase ratio is conducted from the instant the calculated pump impeller suction torque becomes greater than the prescribed criterial value.Type: GrantFiled: June 4, 2002Date of Patent: March 23, 2004Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Eijiro Shimabukuro, Naohisa Morishita
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Patent number: 6146309Abstract: A torque converter automatic transmission of a motor vehicle is equipped with an overheat prevention system of the torque converter.Type: GrantFiled: October 7, 1999Date of Patent: November 14, 2000Assignee: Nissan Motor Co., Ltd.Inventors: Kenji Nishino, Yuji Hayashi
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Patent number: 5921884Abstract: A control system for an automatic transmission includes a clutch for transmitting the rotation of a fluid transmission unit to a speed change mechanism of a transmission and a hydraulic servo for applying/releasing the clutch. A stop state detector is provided for detecting the stop state of the vehicle. A release control oil pressure changer lowers the oil pressure of the hydraulic servo by a first set pressure when the vehicle stop state is detected. An in-neutral control oil pressure changer raises the oil pressure of the hydraulic servo by a second set pressure, when the difference between the input side RPM and the output side RPM of the fluid transmission unit has not changed, and lowers the same by a third set pressure when the rotational speed difference has changed. The first set pressure is different from the second and third set pressures.Type: GrantFiled: September 4, 1997Date of Patent: July 13, 1999Assignee: Aisin Aw Co., Ltd.Inventors: Jiro Nishiwaki, Mitsuhiko Ando, Takahiro Yamashita
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Patent number: 5772557Abstract: A control system for an automatic transmission, including a frictional engagement element, an adjusted oil pressure producing mechanism for adjusting an oil pressure supplied from an oil pressure source to produce an adjusted oil pressure, a hydraulic servo for applying/releasing the frictional engagement element on the basis of the adjusted oil pressure, an engine load detecting mechanism, a vehicle speed detecting mechanism, an up-shift deciding mechanism for determining whether an up-shift has been executed, and a pressure regulate signal generating mechanism for calculating the regulated target pressure of the adjusted oil pressure, when the up-shift is executed, to output a pressure regulate signal. The adjusted pressure signal producing mechanism corrects the regulated target pressure on the basis of the difference between the present vehicle speed and the vehicle speed at a shift point when the shift is executed under the present engine load.Type: GrantFiled: December 24, 1996Date of Patent: June 30, 1998Assignee: Aisin AW Co., Ltd.Inventors: Masayuki Tasaka, Kenji Suzuki, Yoshihiro Yamada, Shinichi Matsui, Tatsuyuki Yoneda
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Patent number: 5709629Abstract: A signal detector is located before an automatic transmission for detecting timing such that torque outputted from a torque converter of the automatic transmission at the moment of upshifting changes from clutch before shift to clutch after shift. A signal detector is located after the automatic transmission for detecting timing such that torque outputted from a torque converter of said automatic transmission at the moment of downshifting changes from clutch before shift to clutch after shift. An apparatus executes the driving shaft torque control in response to the changes in both torque signal detectors.Type: GrantFiled: April 11, 1996Date of Patent: January 20, 1998Assignee: Hitachi, Ltd.Inventors: Toshimichi Minowa, Yoshiyuki Yoshida, Kenichirou Kurata, Tatsuya Ochi
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Patent number: 5685799Abstract: A control for an automatic transmission minimizes shift cycling between adjacent speed ratios due to non-ideal load conditions such as grade climbing and trailering. The control utilizes shift schedule data in formulating a determination of the ability of the vehicle to maintain current levels of performance if an upshift were to occur and inhibits such upshifts where the determination so indicates an inability to meet the criteria.Type: GrantFiled: July 1, 1996Date of Patent: November 11, 1997Assignee: General Motors CorporationInventors: William Joseph Vukovich, Melissa Mei Koenig
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Patent number: 5665024Abstract: A method of determining the deterioration of automatic transmission fluid by detecting shudder during the EMCC portion of air conditioner clutch engagement. Shudder is detected by calculating the acceleration of the turbine during EMCC slip with the following equation:.SIGMA..alpha..sub.t =.SIGMA..alpha..sub.t (i-1)+.alpha..sub.twhere .alpha..sub.t represents the absolute value of turbine acceleration. In a preferred embodiment, the turbine acceleration is summed for twenty-eight periods of 7 msec each after the start of EMCC and the determination that shudder occurred made if the resulting value exceeds a predetermined number. In a further preferred embodiment, the method is used to modify the air conditioner compressor clutch engagement sequence. Once it is determined that shudder is occurring during the EMCC portion of the air conditioner compressor clutch engagement sequence, the EMCC portion of the air conditioner clutch engagement sequence is eliminated or bypassed.Type: GrantFiled: March 28, 1996Date of Patent: September 9, 1997Assignee: Chrysler CorporationInventors: Maurice B. Leising, Hans Dourra, Howard L. Benford
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Patent number: 5637052Abstract: In a control system for controlling motor vehicles in such a manner that the drive force of the vehicle is determined by the accelerator pedal stroke and the vehicle speed, the fuel consumption is minimized by appropriately selecting the gear ratio of the power transmission system under each current operating condition. In particular, the present invention accounts for the slip ratio of the lock-up clutch as well as the transmission efficiency of the torque converter by noting the fact that the lock-up clutch operates under semi-tight conditions as well as under tight and loose conditions.Type: GrantFiled: December 22, 1995Date of Patent: June 10, 1997Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Toshiaki Hirota, Hisashi Igarashi, Yoshiharu Saito, Jun Takahashi, Akira Kato, Toru Kitamura
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Patent number: 5562567Abstract: A motor vehicle having an automatic transmission coupled to an internal combustion engine includes computer based control of powertrain functions including engine torque management and ratio change controls. Shift pressure is scheduled off of the total torque to be transferred to the on-coming friction element, estimated as a function of transmission input torque and powertrain inertia torque constituents. Engine torque during a shift is reduced in a manner which accounts for the relative contributions of transmission input torque and inertia torque constituents of shift torque in order to arrive at a predetermined target shift torque regardless of the proportion mix of the torque constituents.Type: GrantFiled: June 30, 1995Date of Patent: October 8, 1996Assignee: General Motors CorporationInventors: Melissa M. Koenig, William J. Vukovich
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Patent number: 5349885Abstract: An automatic transmission includes a multi-speed transmission gear mechanism having an input shaft, an output shaft and a plurality of friction coupling elements. A hydraulic control system selectively supplies a hydraulic pressure to the friction coupling elements, thereby selectively applying the friction coupling elements to cause the transmission gear mechanism to shift to a speed which is determined according to a predetermined shift pattern. The control system sets a target hydraulic pressure to be applied to the friction coupling elements according to the kind of the shift to be effected and the engine load, and, when it is detected that the transmission gear mechanism is to make a backout upshift due to reduction in the engine load, increases the target hydraulic pressure by an amount which is determined according to the throttle opening and the turbine speed.Type: GrantFiled: August 27, 1992Date of Patent: September 27, 1994Assignee: Mazda Motor CorporationInventors: Hiroshi Yoshimura, Kazuo Sasaki, Kenji Kurisu, Takuji Fujiwara, Mitsutoshi Abe