Abstract: A vehicle hydraulic pressure supply device that includes a mechanical oil pump driven by a drive force source for wheels; an oil passage constitution member in which an oil passage connected to the mechanical oil pump is formed; and a hydraulic control device that controls a hydraulic pressure supplied from the mechanical oil pump via the oil passage constitution member and that supplies the hydraulic pressure to a vehicle drive transmission device.

Abstract: A control apparatus for an automatic transmission including three frictional engagement elements is configured to set engagement pressures of first and second frictional engagement elements at the time when a predetermined shift speed is established such that a torque capacity of a third frictional engagement element becomes smaller than torque capacities of the first and second frictional engagement elements in the case where an engagement pressure is generated in the third frictional engagement element at the time when the predetermined shift speed is established.

Abstract: A vehicle includes torque sources, a transmission, and a controller programmed to execute a method. In executing the associated method, the controller determines whether continuous output torque is required through a torque exchange. When continuous output torque is required, the controller synchronizes and fills the oncoming clutch, estimates capacity of the oncoming clutch, and expands a short-term torque capacity of the oncoming clutch during the torque exchange, doing so in response to a control objective having a threshold priority. Onset of the torque exchange delays until the short-term torque capacity is sufficient for receiving all torque load from the offgoing clutch without affecting output torque.

Abstract: A hydraulic pressure control apparatus for an automatic transmission may include a first hydraulic pump connected with an oil tank to receive oil from the oil tank, having a first motor, and adapted to generate a low pressure through an operation of the first motor, a second hydraulic pump connected with the first hydraulic pump to receive the low pressure, having a second motor, and adapted to generate a high pressure through an operation of the second motor, a first regulating valve adapted to receive the low pressure from the first hydraulic pump and to regulate a first operating pressure to supply to the torque converter, and a second regulating valve adapted to receive the high pressure from the second hydraulic pump and to regulate a second operating pressure to supply to the powertrain.

Abstract: During a non-shift operation when a predetermined gear of an automatic transmission is kept, a hydraulic control unit increases an engagement hydraulic pressure to a friction engagement device associated with the gear formation by a predetermined hydraulic pressure with respect to a line hydraulic pressure. Therefore, in comparison with a case where a hydraulic pressure equivalent to the line hydraulic pressure is set as an engagement hydraulic pressure to the friction engagement device for obtaining a hydraulic pressure equivalent to the line hydraulic pressure, shift response (hydraulic pressure response) variations when shifting from a non-shift state (steady state) into a shift state are suppressed by the margin of the predetermined hydraulic pressure. In addition, in comparison with a case where the engagement hydraulic pressure to the friction engagement device is set to a maximum hydraulic pressure to reduce the response variations, power consumption of each linear solenoid valve is suppressed.

Abstract: Systems and methods are provided for controlling an amount of torque generated by an engine of a vehicle. The amount of torque may be controlled by limiting an amount of fuel or air or a combination thereof being provided to the engine. In some situations, controlling the amount of torque generated by the engine may be utilized to gradually limit the vehicle's acceleration, which in turn, may influence driver shifting strategies.

Abstract: A method for controlling the oil supply device of an automatic planetary transmission, having a main oil pump and an auxiliary oil pump. The transmission is part of a parallel hybrid vehicle powertrain. To supply oil to the transmission as needed, the current oil requirement of the transmission is determined depending on at least one current operating parameter. The auxiliary pump delivery rate is set by actuating the electric motor, in the combustion and combined driving mode below a minimum main oil pump input speed and in the electric driving mode to at least the total oil requirement, and at least in the combined driving mode above the minimum main oil pump input speed is set to at least the residual oil requirement exceeding the delivery rate of the main oil pump.

Abstract: A lubricating oil supply control device for delivering lubricating oil to the transmission of a vehicle is provided which overcomes disadvantages of the prior art by providing a simple and reliable configuration which does not require the addition of new sensors to an existing device. The lubricating oil supply control device includes, in part, an engine controller and a transmission controller, a lubricating oil supplying oil passage, a bypass oil passage, a relief valve or a control valve, a restrictor, and a lubricating oil supply controlling controller.

Abstract: The adjustment method includes an estimation step in which valve characteristics of the linear solenoid valves fitted to the hydraulic control circuit are measured, and estimated linear valve characteristics of the linear solenoid valves in isolation state are estimated based on the measured valve characteristics using predetermined correlations; and a correction value output step in which estimated linear piston-end pressures of the hydraulically-driven friction engagement elements immediately before the hydraulically-driven friction engagement elements are engaged are calculated based on the estimated linear valve characteristics, and the correction values that are applied to the control command values to adjust the drive currents supplied from the valve control unit to the linear solenoid valves are calculated based on differences between the estimated linear piston-end pressures and nominal piston-end pressures, and then output.

Abstract: When an engine is in operation an ignition switch is turned off by a driver an ECU executes a program including the step of actuating an electric motor driven oil pump.

Abstract: An ECU executes a program that includes a step of determining whether an output shaft rotation speed NOUT is equal to or greater than a reference rotation speed at which determining regions with all of the gear speeds in a stepped automatic transmission do not overlap, a step of determining that there is an abnormality in the gear speed by dividing the turbine rotation speed NT by the output shaft rotation speed NOUT if the output shaft rotation speed NOUT is not equal to or greater than that reference rotation speed, and a step of determining that there is an abnormality in the gear speed by subtracting a value, which is obtained by multiplying the output shaft rotation speed NOUT by the gear ratio, from the turbine rotation speed NT if the output shaft rotation speed NOUT is equal to or greater than that reference rotation speed.

Abstract: A gear shift controlling apparatus of an automatic transmission for a vehicle has a synchronization-time engagement pressure correcting device that, before synchronization of gear-shifting, makes an increase correction of an engagement pressure of the disengaged-side engaging element by a first prescribed amount, to cause an input shaft rotational speed immediately before synchronizing of the automatic transmission to approach a rotational speed calculated by multiplying an output shaft rotational speed by a gear ratio of a gear after gear-shifting the automatic transmission.

Abstract: A control valve arrangement having a clutch regulation valve (3), which pressurizes a device to actuate the clutch, and a valve that produces a controlled pilot pressure (P_VST3). An electronic control unit (ECU) controls a valve to supply a control valve with the pressure (P_VST3). The arrangement further having a hydraulic system which, if the ECU fails and the pressure (P_VST3) ceases, the last shift condition of the clutch actuation device, prior to the ECU failure, can be maintained in an emergency. The arrangement includes a valve, which delivers an activation pressure (P_A), depending on an engine-speed-dependent control pressure (P_D), to an actuation valve (2), which then delivers the pressure (P_A) to the valve (3) to prevent the emergency function initiation despite a lack of pressure (P_VST3) and existence of the pressure (P_D) sufficiently high to initiate the emergency function.

Abstract: A valve assembly for controlling actuation of at least one starting clutch of an automatic transmission includes at least one clutch control valve through which a supply pressure is directed to a clutch actuation device, a pressure control valve controlled by a control device to supply at least one control valve of the valve assembly with a pilot pressure, a self-maintained hydraulic unit to maintain operation of an engaged starting clutch upon failure of the control device and loss of the pilot pressure. The valve assembly has a self-maintained valve and an activation valve. The self-maintained valve directs an activation pressure or control pressure, depending on the engine or transmission speed, to the activation valve. The actuation valve directs the activation to at least one clutch-regulating valve. The valve assembly also controls actuation or de-activation of the emergency operation function with a clutch actuation pressure.

Abstract: A control valve arrangement for controlling a start coupling of an automatic gearbox comprising a clutch control valve (3, 37, 41, 48, 49) for controlling at least one clutch actuating device (4, 40) which, during normal operation of the gearbox, converts a supply pressure input (P_V1, P_V2) into a clutch actuation pressure (P_K, P_K1, P_K2) according to a pre-control pressure or an electric pre-control signal in order to control the clutch actuation device. An activating pressure (P_A) can be supplied to the clutch control valve or directly to the clutch activation device in the event of a discontinuation of the pre-control pressure or pre-control signal according to the engine and gearbox output speed, whereupon the clutch actuation device is maintained in a closed position as long as the above mentioned speed remains above a predetermined limit.

Abstract: A shift control method of an automatic transmission that controls a shift from an nth shift speed, achieved by engagement of first and second friction elements, to an (n?3)th shift speed, achieved by engagement of third and fourth friction elements. The method includes releasing the first and second friction elements and engaging the third and fourth friction elements. Release control of the second friction element begins after release control of the first friction element begins. Engagement control of the fourth friction element begins after an engagement control of the third friction element begins.

Abstract: A drive control system for an automotive vehicle includes an engine, an automatic transmission, a torque converter, a start clutch, an oil pump, a hydraulic pressure control unit, an engine control unit, an automatic engine stop/restart control unit and a torque transmission control unit configured to calculate target start clutch engagement time and torque based on an accelerator opening of the vehicle, calculate a target engine torque based on the target clutch engagement torque and cause the hydraulic control unit and the engine control unit to control the engagement state of the start clutch and the output torque of the engine according to the target clutch engagement time and torque and the target engine torque at a restart of the engine.

Abstract: Hydraulic pressure supplied to a first brake and a second brake in a transmission is controlled during an upshift such that the second brake releases from an applied state, and the first brake applies from a released state. The hydraulic pressure supplied to the first brake is increased to a standby pressure. When a period of time has passed after the upshift starts, the output torque of a powertrain is increased. The standby pressure is corrected according to a decrease rate of an input shaft rotation speed of the transmission during an inertia phase of the upshift. An ECU executes a program that includes the step of setting the period of time from the start of the upshift until the output torque of the powertrain starts to increase, according to the standby pressure.

Abstract: A shift control method of an automatic transmission according to an exemplary embodiment of the present invention may control a shift from an N speed achieved by engagement of first and second frictional elements to an N?3 speed achieved by engagement of third and fourth frictional elements, wherein release of the second frictional element is completed after release of the first frictional element begins, and engagement of the fourth frictional element begins after engagement of the third frictional element begins, wherein the engagement of the third frictional element is completed after the release of the second frictional element is completed.

Abstract: A control apparatus for a vehicular automatic transmission includes a control portion that executes a neutral control in which the control portion places the automatic transmission in a neutral state by reducing an application load on a frictional apply device inside the automatic transmission when the vehicle is stopped. The control portion ends the neutral control when a torque transmitted to the frictional apply device has been continually equal to, or greater than, a predetermined value for a consecutive predetermined of time. As a result, by considering the torque transmitted to the frictional apply device in addition to the continuation time of the neutral control, it is possible to more precisely grasp the state of the frictional apply device. In other words, it is possible to execute, as quickly as possible, neutral control for an extended period of time while ensuring durability of the frictional apply device.

Abstract: In a gearbox control system (8) for detecting systematic errors and long-term changes, the behavior of a real gearbox (1) is compared to the behavior of an ideal gearbox (7), which is implemented in the form of a gearbox model in the gearbox control system (8).

Abstract: Under the learning mode during a vehicle stationary condition, an oil pressure of the friction engagement element for setting a standby oil pressure value is increased by a predetermined step pressure while a transmission input shaft rotational speed has been maintained, and a standby oil pressure is set for shifting the friction engagement element to an engagement side. A controlled value is verified whether it is within a predetermined range corresponding to the predetermined step pressure when a change of the input value due to decrease of the turbine rotational speed satisfies a predetermined condition. The controlled value is learned when the controlled value is within the predetermined range corresponding to the step pressure. A step pressure larger than the step pressure is set when the controlled value is beyond the predetermined range corresponding to the step pressure.

Abstract: A shift control apparatus of an automatic transmission of a motor vehicle to which torque is transmitted from an engine via a fluid coupling device is provided. In the automatic transmission including a plurality of hydraulically operated friction elements, a clutch-to-clutch downshift is carried out during coasting of the vehicle by releasing one of the friction elements and engaging another friction element. A controller of the shift control apparatus detects a difference between input and output rotation speeds of the fluid coupling device, and increases an engine speed by a controlled amount based on the difference between the input and output rotation speeds when the clutch-to-clutch downshift is carried out during coasting of the vehicle, so that the vehicle is brought into a minimal driving state in which the engine speed is slightly higher than the output rotation speed of the fluid coupling device.

Abstract: Each control portion for controlling each friction element includes a switch valve and pressure control valve such that hydraulic pressure supplied to the friction element is fully controlled, and a control portion for controlling a friction element that is operated both at low and high speeds includes a switch valve that senses an operation of a friction member cooperatively with the friction element at the high speed such that the friction member receives different hydraulic pressure at low and high speeds. A plurality of fail-safe valves is included for enhancement of a fail-safe function of an automatic transmission.

Abstract: When it has been determined that control for a predetermined upshift has been started while an accelerator pedal was not being depressed, and that a factor that changes an input torque of an automatic transmission has been generated, an engaging pressure of a predetermined hydraulic frictional engagement device is corrected by a correction amount in accordance with the factor that changes the input torque. As a result, undershooting of an engine speed, as well as shift shock which results from that undershooting, is able to be preferably suppressed.

Abstract: A judging section judges whether or not ranges detected, respectively, by a first range detection section consisting of a first detection section and a position detecting sensor, and a second range detection section consisting of a second detection section; a C1 detecting sensor and a B1 detecting sensor are in mutual agreement, and when the detected ranges are not in mutual agreement, a failure judging section judges a failure of the first range detection section.

Abstract: A belt type continuously variable transmission (CVT) (10) for a vehicle varies the speed ratio in accordance with the hydraulic pressure that is regulated via a hydraulic pressure regulating unit (30). A sensor (27) detects a vehicle speed. A CVT controller (20) calculates a target hydraulic pressure that is supplied to the CVT (10) on the basis of a predetermined speed change schedule so that the speed ratio varies in the direction of up-shifting as the vehicle speed increases (S15). The CVT controller (20) also determines whether or not a specified condition holds (S16, S160), and controls the hydraulic pressure regulating unit according to a target start-up hydraulic pressure which is larger than a target hydraulic pressure for normal running (S11, S13), thereby preventing a speed change lag when the vehicle starts to move.

Abstract: A control system for a transmission comprising a torque converter or a hydrodynamic clutch in a motor vehicle, at least one torque-conducting clutch or brake in the starting operation of the motor vehicle. It is proposed to regulate the starting power of the motor vehicle as function of a driver's wish, via a slip clutch or brake mounted in the transmission, taking into account parameters of the torque converter and/or hydrodynamic clutch.

Abstract: In a vehicle wherein the output of an engine is transmitted to an output shaft via a torque converter and clutches, for forward/reverse change-over, a control device is provided which can control a creep phenomenon. The control device comprises a change-over valve provided in a circuit for supplying the pressurized fluid to the clutches, and the pressure control valve which controls the fluid pressure to the clutches. When the accelerator pedal is not depressed, the pressure control valve is controlled to make the vehicle speed lie within a predetermined target speed range.

Abstract: A downshift control determines whether a commanded downshift is a downshift oriented toward minimum shock or a downshift oriented toward responsiveness, based on inputs from various sensors. The oil pressure on the hydraulic servo which controls the releasing-side friction engagement element is controlled based on the determined downshift type (DT), so that the releasing-side friction engagement element is released in accordance with a selected one of a plurality of release patterns, i.e., release patterns corresponding to different downshift type indexes (Dt). The releasing speed of the releasing-side friction engagement element is changed in accordance with the downshift type. By properly determining the type of downshift, it becomes possible to realize a shift of a type in accordance with the driver's intention.

Abstract: A control device for an automatic transmission has a torque transmission provided between an input shaft and an output shaft of a gear-type transmission The torque transmission in at least one change gear stage is a friction clutch. When performing a change gear from one change gear stage to another change gear stage, the friction clutch is controlled. A transfer torque capacity detector detects or computes transfer torque of the friction clutch when performing a change gear to a predetermined change gear stage, and a clutch release timing determining apparatus determines a timing when releasing the claw-type clutch into a neutral state based on the value detected or computed by the torque capacity detector.

Abstract: A driver authentication apparatus and method permits a vehicle driver to be identified using a simpler method without using an ID card or the like, and without performing any special operation. The apparatus has a feature amount storing section for storing preset feature data of each registered driver; an operation detecting section for detecting an operation performed by the driver, and outputting data indicating details of the operation; and a feature data managing section for storing the data output from the operation detecting section and generating operation feature data of the driver based on the stored data, and comparing the operation feature data with the preset feature data stored in the feature amount storing section and determining any identity between the compared operation and preset feature data.

Abstract: An improved control for an automatic transmission garage shift, wherein a dynamic model of the transmission is used to estimate the transmission input torque during the shift and to schedule the on-coming clutch pressure in accordance with the estimated input torque to achieve a desired input shaft trajectory. The transmission input torque is estimated based on two different methodologies —one suited to steady-state engine idle conditions, and the other suited to engine output torque transient conditions. A fuzzy summation of the input torques provided by the two methodologies is utilized in transitions between the two conditions. Shift quality variations due to variations in mechanical and/or hydraulic stiffness are minimized by a pause or hold interval inserted between the end of the fill period and the initiation of on-coming clutch pressure control, which results in a reasonably consistent degree of perceived transmission-to-transmission hydraulic and mechanical compliance.

Abstract: A control apparatus and a control method for an automatic transmission, minimizes torque fluctuations which, if left unchecked, give vehicle passengers a disagreeable feeling upon a gear shift. The control apparatus and method suppresses, such torque fluctuations during a shift of the transmission to improve robustness and provide good shift characteristics. An inertia phase is recognized in which the engine speed starts to drop during the shift. At the beginning of the inertia phase, hydraulic pressures supplied to frictional engaging devices in the transmission are kept constant to suppress the torque fluctuations.

Abstract: A system for controlling an automatic transmission of a vehicle, wherein the hydraulic pressure to be supplied to the frictional engaging element such as a hydraulic clutch is determined, taking the performance of tracking or follow-up of the hydraulic pressure into account so as to enhance the control toughness against the engine speed change, thereby decreasing the shift shock effectively so as to improve the feeling of the vehicle occupant, while ensuring to prevent the engine from revving over or excessively. Further, the friction coefficient of the hydraulic clutch is calculated additionally taking parameters including the rotational difference thereof into account to determine the pressure to be supplied to the frictional engaging element, thereby further decreasing the shift shock effectively.

Abstract: A system for controlling an automatic transmission of a vehicle, wherein the initial value of the desired pressure to be supplied to a hydraulic clutch for the current gear now being engaged is determined appropriately, when conducting a power-on downshifting, so as to decrease the shift shock experienced by the vehicle occupant effectively, irrespectively of the change in he throttle opening, while ensuring to reduce the volume of the mapped data.

Abstract: Disclosed herein is a speed change transition control apparatus for an automatic transmission. The speed change transition control apparatus comprises rotational speed detection unit for detecting an input shaft rotation speed of the speed change mechanism, and a feedback control unit for controlling engagement pressure through a fluid pressure control element in such a manner that the input shaft rotation speed during a speed change follows a target rotation slope with an actual input shaft rotation speed detected at an actual inertia phase start point by the rotational speed detection unit as its starting point.

Abstract: A controller (61) for a line pressure control device of a transmission (200) determines whether or not a vehicle speed is above a fixed vehicle speed. The controller (61) set a target line pressure in response to a torque input into said transmission (200) when the vehicle speed is lower than the fixed vehicle speed. When the vehicle speed is higher than the fixed vehicle speed, the target line pressure is increased to a fixed hugh line pressure irrespective of the torque input into the transmission (200). In this way, it is possible to prevent deficiencies in an amount of lubricant when the vehicle is running at a high speed.

Abstract: A control system for a CVT comprises a controller arranged to compute an engine revolution condition on the basis of an engine revolution speed indicative signal, to compute actual and estimated engine outputs on the basis of the engine revolution condition, to compute a rotational change condition of the drive system, to compute an actual input load change amount caused by the inertia by multiplying the actual rotational change condition detection value by a predetermined inertial constant, to compute an estimated input load change amount by multiplying the estimated rotational change condition detection value by a predetermined inertia coefficient, to select larger one of the actual input load change amount and the estimated input load change amount as the input load change amount for outputting a command signal, and to output the command signal to a line pressure duty valve on the basis of the engine output and the selected input load change amount so as to further accurately control a line pressure.

Abstract: An automatic transmission control system for an automatic transmission including a hydraulic pressure control circuit which supplies locking and unlocking pressures selectively to a plurality of friction coupling elements to lock and unlock the selected friction coupling elements, changing a torque transmission path in a transmission gear mechanism to provide available gears, a specific one of which is achieved by locking and unlocking simultaneously specific friction coupling elements.

Abstract: An automatic transmission control system is capable of quickly and accurately judging the normal state and faulty state of an input shaft rotation speed sensor and/or an output shaft rotation speed sensor. The system includes an input shaft rotation speed sensor condition judging device for judging whether an input shaft rotation speed sensor detecting a rotation speed NI of an input shaft of the automatic transmission is in a normal or faulty state, an output shaft rotation speed sensor condition judging device for judging whether an output shaft rotation speed sensor detecting a rotation speed No of an output shaft of the automatic transmission is in a normal or faulty state, a multiplying means for multiplying the rotation speed No of the output shaft with a current transmission gear ratio, and comparing and judging means for judging whether the multiplied value is coincident with the rotation speed NI of the input shaft.

Abstract: A hydraulic pressure control apparatus for an automatic transmission including a microprocessor-based control unit for controlling hydraulic pressure supplied to hydraulic servos of friction engagement elements. The control apparatus calculates a target hydraulic pressure P.sub.TA for a condition at the start of the inertia phase in accordance with the input torque, and a gradient based on the target hydraulic pressure and a predetermined time t.sub.TA. A first up-sweep of hydraulic pressure is performed by the apparatus with the gradient. A relatively gradual gradient .delta.P.sub.TA is set based on a target rotation change rate for the input rotational speed to provide a predetermined change amount when the hydraulic pressure becomes the target hydraulic pressure P.sub.TA. The control apparatus performs a second up-sweep with the gradient .delta.P.sub.TA. When the rotational speed change .DELTA.N of the input rotation becomes a rotation change start-determining rotational speed dN.sub.

Abstract: A motor vehicle shift control apparatus wherein two hydraulically operated frictional coupling devices are simultaneously released and engaged, respectively, to effect a clutch-to-clutch shift of an automatic transmission, including an overshoot control device for compensating the hydraulic pressure of at least one of the coupling devices during the clutch-to-clutch shift such that the amount of engine speed overshoot is held within a predetermined range, and an inhibiting device for inhibiting an operation of the overshoot control device if a preventing device for preventing an excessive rise of the engine speed above an upper limit is expected to be activated, or if the preventing device is in operation. The inhibiting device may be replaced by a device for reducing the output of the engine if the engine speed is higher than a threshold not higher than the upper limit.

Abstract: A hydraulic control system for an automatic transmission comprising a shift speed mechanism, a frictional element hydraulically controlled for switching a power transmitting path in the shift speed mechanism, a working pressure controller for controlling an engaging force of the frictional element during a shift operation by adjusting a working pressure applied to the frictional element, a calculator for calculating separately an input torque pressure corresponding to an input torque introduced to the shift speed mechanism and an inertia torque pressure corresponding to an inertia torque which is changed in accordance with a speed change of the shift speed mechanism, and a learning control compensator for compensating the inertia torque pressure by means of a learning control. The shift shock is effectively suppressed irrespective of the change of the vehicle operating circumstance.

Abstract: A control system for an automatic transmission for a vehicle provides an enhancement in a shifting characteristic in a manually shifting mode by controlling an operating hydraulic pressure for hydraulic engage elements in an appropriate manner. In a first range from the output of a shifting command to a time point when a timer TOIPU reaches a counting-up value, or a time point when the slip rate ECL of the hydraulic engage elements exceeds a value YECLIPUS, the operating hydraulic pressure is set at a preset value depending upon the type of shifting. In a second range from the end of the first range to a time point when the timer TOIPU reaches a counting-up value, or a time point when a slip rate ECL exceeds a value TECLIPUS, and in a third range from the end of the second range to a time point when a timer TKAK reaches a counting-up value, the operating hydraulic pressure QAT is set at a value corresponding to an engine torque or a transmission input torque.

Abstract: A controller (100 in FIG. 1) for relieving a gear shift shock in a vehicle, having an input torque calculation portion (131) which calculates the input torque (T.sub.t) of the stepped automatic transmission mechanism of the vehicle from engine r.p.m. (N.sub.e) and turbine r.p.m. (N.sub.e), a shift start recognition portion (134) which recognizes the real mechanical shift start timing of the stepped automatic transmission mechanism in accordance with the change of the input torque (T.sub.t), a line-pressure correction magnitude calculation portion (142) which calculates a line-pressure correction magnitude (.DELTA.PL) during the gear shift operation of the stepped automatic transmission mechanism when the shift start has been recognized, a standard line pressure calculation portion (143) which calculates a standard line pressure (PL), and a command line pressure calculation portion (144) which adds the line-pressure correction magnitude (.DELTA.

Abstract: The invention relates to a process for the adaptive correction of the shifting quality of an automatic transmission which is coupled to an engine and in which correcting elements acting on the pressure or oil throughput bring friction elements into engagement in the form of clutches or brake bands to carry out shifting processes, the line pressure impinged on by the correcting elements being registered by means of an electronic device and corrected as a function of various operating parameters.

Abstract: A hydraulic control system for an automatic transmission, the system including: a fluid pump; a proportional control valve for reducing a hydraulic pressure in accordance with a vehicle speed; a valve body including a line pressure inlet port for receiving the hydraulic pressure compressed by a fluid pump, a line pressure outlet port for flowing out the hydraulic pressure to be used as a driving pressure in a "D" range; a reverse pressure port for flowing out the hydraulic pressure to be used as the driving pressure in an "R" range; and a first, a second, a third and a fourth speed ports for receiving the hydraulic pressure from the line pressure outlet port and for flowing out the hydraulic pressure to shift a speed stage in accordance with a vehicle speed; a manual valve rotatably disposed in the valve body and rotates in accordance with a movement of a shift lever; and a shift control valve rotatably disposed in a same concentric axis with said manual valve in the valve body; the manual valve including a n

Abstract: A hydraulic control for an automatically shifted power transmission has an electronically controlled governor pressure source which provides a speed and throttle sensitive pressure for controlling the shift points and trim boost in the transmission control. An inhibitor circuit is activated in the event of a discontinuance of the electrical control, resulting in maximum governor pressure, to permit selected vehicle operation in one forward ratio and a reverse ratio. Each ratio interchange is controlled by a respective shift valve and clutch control valve. Each clutch control valve has an integral trim control which is effective to control the pressure rise in the on-coming clutch without bypassing fluid to an exhaust. Also during a ratio interchange, an off-going clutch is controlled at a reduced pressure during a portion of the ratio interchange.

Abstract: 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.