Abstract: An electro-hydraulic transmission control has a pair of solenoid valves which are energized individually to provide a forward drive or a reverse drive. A mode mechanism downstream of the solenoid valves is actuated to a forward or reverse mode depending on which solenoid is actuated. The hydraulic fluid downstream of the solenoid valves is also effective to actuate one of two disable valves. When the forward solenoid is selected, the reverse disable valve is actuated and vice versa. In the event that hydraulic pressure is inadvertently directed to the forward and reverse drives simultaneously, both disable valves are actuated and the transmission control is placed in neutral.

Abstract: When a shift to a second gear ratio (second ratio) is determined during a shift control for a first shift (shift from fourth ratio to third ratio), the process status, or circumstances, of the first shift is determined using a hydraulic pressure for a fourth brake being engaged at the determination. When the process status, that is, the process circumstances, is in early phase, the first shift is interrupted and shift control for the direct shift to the second ratio (shift from fourth ratio to second ratio) is performed (first shift pattern). When the process status is in a late phase, the first shift control is continued, and after ending of the first shift control, the control for the shift to the second gear ratio (shift from third ratio to second ratio) is performed (second shift pattern). In the case of power off state, the second shift pattern is performed irrespective of the process status.

Abstract: A process is provided for operating a vehicle transmission with preferably electrohydraulically actuatable friction elements for shifting between different transmission steps, in a vehicle with at least one drive engine in which an actual value of at least one of the quantities characterizing the shift process is determined for each shift process, which actual value is compared with a theoretical value that can be established and stored. When the actual value deviates from the theoretical value, a regulated quantity for at least direct influencing is changed by a correction value that can be established. For each shift process, the time duration for the output of a gear shift signal up to the beginning of the synchronization process and/or the change of the drive rpm during this time period is determined as a first and/or second actual value of the quantity characterizing the process.

Abstract: A fuzzy control method of a damper clutch and, more particularly, a fuzzy control method enhances engine brake effect by directly connecting a pump to a turbine by engaging the damper when a shift control unit identifies an engine brake state. The fuzzy control method of a damper clutch includes receiving or checking input signals relating to a damper clutch; controlling shift timing by a fuzzy control; determining if an engine brake should be used or not; checking an amount of driver's engine brake will if the engine brake should be used; determining if an emergency brake should be used or not; engaging the damper clutch when an emergency brake should be used; and controlling the damper clutch through a normal control when both the engine brake and emergency brake are not used.

Abstract: The present invention is a control device and a control method for a transmission with a clutch, by which the clutch is smoothly coupled without generation of shocks or the like in a vehicle.

Abstract: An apparatus for controlling an automatic transmission of a motor vehicle, wherein a shift-down action of the automatic transmission is achieved with a releasing action of a hydraulically operated frictional coupling device, the apparatus including a rapid pressure reduction device operated upon determination that the shift-down action should be effected, for rapidly reducing a pressure of the frictional coupling device to a predetermined pressure level higher than a critical level at which the frictional coupling device starts slipping, an input torque determining device for determining an input torque of the automatic transmission, or a rate of increase of the input torque, and a rapid pressure reduction amount determining device for determining the predetermined pressure level to which the pressure of the frictional coupling device is reduced, on the basis of the input torque or the rate of increase thereof of the automatic transmission determined by the input torque determining device.

Abstract: A hydraulic control for operating an automatic transmission, especially a continuously variable transmission, has at least one first and one second switching component (1, 2) for forward or reverse drive from a neutral position (N) to a drive (D) or reverse (R) position and vice versa. The switching components (1, 2) can be actuated by pressure via pressure lines (24, 25) by a selector slide (15) and by a switching device (26) between the selector slide (15) and the switching components (1, 2) which has a switching valve (27, 28) and a damper, switching and vent valve (29, 30) for a switching component (1, 2). The switching device (26) has a safety and vent device designed in a manner such that when one of the switching components (1, 2) is actuated, the other switching component(s) is/are automatically disengaged.

Abstract: A gear control for reduces the thermal stress on switching components (2, 3, 4, 5, 6) of a reversing gear (1) for machines having an input shaft (8) and an output shaft (15) and at least one directional switch for forward motion (2) and one for reverse motion (3) and a downstream load-switchable switching set (4) with several switching components (5, 6) allocated to a gear. Here the switching components (2, 3, 5, 6) can be electrically and/or hydraulically controlled by a regulating and control device (12) in such a way that, during a switching operation, in addition to one of the directional switching components (2, 3) corresponding to the switching operation, at least one other switching components (5, 6) of the downstream switching set (4) lying in the power flow and fully engaged at the start of a reversal is set to a slip state under frictional load. The frictional load is thus distributed between the directional switching components (2, 3) and the other slipping switching components (5, 6).

Abstract: Upshifting is performed in a short time without giving rise to shocks. For that purpose, at the time of upshifting, a hydraulic pressure (QUPOFF) of a hydraulic engaging element on disengaging side is controlled such that the input and output speed ratio ("Gratio") of a transmission is decreased to, and held at, a predetermined slipping region (YG(N)S) that is lower than an engaging region (YG(N)L)-YG(N)H) to be set based on a gear ratio which is established by the engagement of the hydraulic engaging element on the disengaging side. The hydraulic pressure (QUPON) of a hydraulic engaging element on engaging side is gradually increased. When "Gratio" once falls below YG(N)L and then increases up again to YGCONOK, QUPOFF is lowered to a predetermined low pressure (QUPOFFB) at a lapse of a predetermined time (YTMUP8). Once "Gratio">YGCONOK, QUPON is increased to a predetermined high pressure QUPONB at a lapse of a second predetermined time YTMUP3.

Abstract: Disclosed is a hydraulic control system for an automatic transmission including a plurality of friction elements associated with respective transmission speeds. The hydraulic control system includes a hydraulic fluid source, a line pressure controller, a reducing pressure controller, a range controller, a shift controller, a hydraulic pressure controller, and a hydraulic pressure distributor.

Abstract: An automatic transmission control system for an automotive automatic transmission including a speed sensor for detecting a vehicle speed of the vehicle, a load sensor for detecting a load acting on the driving torque generator, a torque sensor for detecting input torque transmitted to the automatic transmission from the driving torque generator, first working fluid pressure control communicating both a first friction coupling element's unlocking pressure chamber and a second friction coupling element's pressure chamber with the working fluid source in the hydraulic pressure control system for controlling supply of working fluid pressure to and from both the unlocking pressure chambers and a second working fluid pressure control in the fluid path communicating both the first friction coupling element's locking pressure chamber with the working fluid source for controlling supply of working fluid pressure to and from the first friction coupling element's locking pressure chamber.

Abstract: It is detected on the basis of a change in an engine speed whether an out-of shelf condition in which a gear shft time exceeds a predetermined time is caused or not (step S11), and when the out-of shelf condition is caused, a lapping control processing corresponding to first engaging oil pressure setting means is executed so that a correction value is set to increase a line pressure supplied to each kind of engaging elements of an automatic transmission, and that the correction value is decreased as a gear shft load time elapses. At the same time, a learning control processing corresponding to a second engaging oil pressure setting means is executed (step S17) so that a variation of the engaging oil pressure due to the non-uniformity of engaging elements and the deterioration with age is learned, thereby to enable to automatically act a proper line pressure on each kind of engaging elements when either one of the automatic transmission or a controller which controls the automatic transmission is replaced.

Abstract: A gearshift controller for an automatic transmission comprises an input shaft torque estimating portion for estimating the input shaft torque, a torque dividing ratio setting portion for setting the torque dividing ratio for each friction member of each gear range, and a desired torque calculating portion for calculating the desired torque of each friction member on the basis of the input shaft torque and the torque dividing ratio, and a desired hydraulic fluid calculating portion for calculating the desired hydraulic fluid pressure for each friction member on the basis of the desired torque of the each friction member, and a hydraulic fluid controlling portion for providing the desired hydraulic fluid pressure to each friction member.

Abstract: An apparatus for controlling the pressure of a hydraulically operated frictional coupling device which is released or engaged to achieve a shifting action of an automatic transmission, by first rapidly reducing or increasing the pressure to a predetermined level, holding the pressure at this level for a predetermined time and then continuously reducing or increasing the pressure to complete the shifting action, wherein a learning compensation device is provided to update, by learning compensation, a selected control parameter influencing a pattern of change of the pressure of the coupling device during the shifting action such that the shifting action is achieved in a predetermined manner.

Abstract: Disclosed is a hydraulic control system used in an automatic transmission for a vehicle which includes a plurality of friction elements associated with respective transmission speeds, a hydraulic pressure source, a hydraulic pressure regulating controller for controlling hydraulic pressure from the hydraulic pressure source to constant line pressure, a damper clutch controller for actuating a damper clutch of the torque converter by supplying hydraulic pressure fed from the pressure regulating controller to the torque converter, shift controller for selecting a shift mode by converting hydraulic pressure from the pressure regulating controller into drive pressure corresponding to each speed stage, a hydraulic pressure controller for controlling the drive pressure from the shift controller, and a hydraulic pressure distributor for suitably distributing hydraulic pressure from the hydraulic pressure controller to each friction element for each speed, wherein the hydraulic pressure distributor includes a shift t

Abstract: The present invention prevents shift shock and reduces time required to execute the complete speed change operation in the case where a second speed change is commanded while a first speed change operation is still in progress. If a down-shift to a first speed stage is commanded during an up-shift operation from the first to the second speed, the hydraulic pressure in the second speed change operation is controlled in accordance with the state of the first speed change operation at the time of generation of the command for the second speed change. For example, if a down-shift to the first speed stage is commanded during the torque phase of an up-shift operation from first to second speeds, namely, before change in the rotational speed of the input shaft has started, only completion control of the down-shift operation is executed.

Abstract: A hydraulic control system for an automatic transmission, including a hydrualic pressure source, a hydrualic pressure regulator, a transmission mode selector, a shifting controller for automatically controlling shifting between transmission speeds in a given transmission mode, and a hydrualic pressure control mechanism for controlling quality and responsiveness of the shifting between transmission speeds. The hydrualic control system includes a fail safe valve for assuredly maintaining a certain transmission speed (such as third speed) when a transmission control unit (TCU) fails, or when a valve in the control system sticks or becomes inoperative.

Abstract: When slipping is generated during the upshifting from a first gear shift stage to a second gear shift stage on ice or the like, a control for prohibiting the upshifting from the second gear shift stage to a third gear shift stage can be carried out precisely. A control system is designed so that when a slipping state is detected on ice having a lower road surface friction coefficient by a slipping state determining device, the upshifting of an automatic transmission from a second gear shift stage to a third gear shift stage is prohibited. In this control system, the time required for the upshifting from a first gear shift stage to the second gear shift stage is measured. If such time is shorter than a first predetermined time, it is determined that a slipping has been generated during the upshifting, and the upshifting from the second gear shift stage to the third gear shift stage is prohibited for a second predetermined time.

Abstract: A control apparatus executes appropriate speed change control under any operating conditions encountered during an up-shift by change-over, without requiring an increase in control logic. Engagement side hydraulic pressure is swept up as a result of an arithmetic operation in torque phase speed change control. Disengagement side hydraulic pressure is calculated by initial speed change control, dependent on the engagement side hydraulic pressure. The engagement side hydraulic pressure is directly controlled and the disengagement side hydraulic pressure is indirectly controlled, i.e. responsive to the engagement side control. Consequently, the same control scheme can be executed regardless of power-on state or power-off state and regardless of vehicle operating conditions.

Abstract: A speed change control system for an automatic transmission which includes a plurality of frictional engagement elements and in which a first speed change unit for executing a clutch-to-clutch shift by applying/releasing two frictional engagement elements simultaneously and a second speed change unit for executing a speed change by applying a one-way clutch are connected in tandem. The decision is made upon both the clutch-to-clutch shift of the first speed change unit and the speed change, as effected by applying the one-way clutch of the second speed change unit. At the speed change time, the clutch-to-clutch shift is established before the application of the one-way clutch. According to the present invention, therefore, the clutch-to-clutch shift at the first speed change unit of the automatic transmission, as accompanied by the application of the one-way clutch at the second speed change unit, can be easily controlled to prevent the shift shock.

Abstract: An automatic transmission for an automotive vehicle which includes a hydraulic pump for pressurizing fluid; a pressure regulating valve for varying hydraulic pressure supplied from the hydraulic pump; seven friction elements for forward driving and two friction elements for reverse driving activated according to spool positions of a manual valve, first and second shift control sections having at least two shift valves for supplying hydraulic pressure to the friction elements selectively, and a torque pressure converting section for supplying torque pressure to the first shift control section.

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: Transmission output speed and engine throttle position are inputs to a control which determines acceleration and input speed. Fuzzy logic has acceleration and throttle membership functions and a set of upshift and downshift values, and rules for weighting each of the values in accordance with the degree of membership of acceleration and throttle position in certain of the functions to determine a downshift point and an upshift point. The input speed is compared to the shift points to decide whether to order a shift. Two or more sets of shift values are stored and are selectable for different performance options. The shift values are stated in terms of a percentage of engine governed speed to allow different engines to be coupled to the transmission. Lockup clutch apply and release logic controls converter lockup to maintain converter mode when significant torque multiplication is occurring and generally to maintain lockup mode when the transmission range is at or above the lowest allowable lockup range.

Abstract: An automotive automatic transmission has an input shaft receiving a rotational force from an engine, an output shaft for outputting a rotational force to a vehicle driving wheel, a frictional engagement device having an adjustable engagement condition, and a transmission device for transmitting a rotational force from the input shaft to the output shaft at a gear speed ratio depending on the engagement condition of the frictional engagement device. A control apparatus for the automotive automatic transmission includes an engagement condition adjusting device for adjusting the engagement condition of the frictional engagement device by feeding a hydraulic pressure thereto in response to an instructed control amount.

Abstract: In power-on, high-vehicle-speed and high-torque conditions, a control unit sets a torque allotment ratio such that a main clutch bears all the torque. Thereby, the input shaft rotational speed is increased by controlling solely the main clutch releasing pressure. In power-on and low-torque or low-vehicle-speed conditions, the control unit sets a torque allotment ratio for the main clutch torque and the sub-clutch torque to 1:1. Thereby, control of the main clutch releasing pressure and control of the sub-clutch engaging pressure simultaneously proceed in parallel to produce a change in the input shaft rotational speed without a time lag. The hydraulic control apparatus thus conducts proper downshift control for a shift involving clutch engagement changeover, under all vehicle running conditions, without need for additional control logic.

Abstract: An upshift is effected by releasing an engaged first friction element and engaging a released second friction element. The first fiction element operates on a fluid pressure applied thereto through a first passage and the second friction element operates on a fluid pressure applied thereto through a second passage. An accumulator is provided in the first fluid passage. The accumulator has a back pressure port through which a back pressure is applied thereto by the function of a control valve having a first port connected to the back pressure port, a second port connected to a source of back pressure and a third port connected to a drain. The control valve operates, between a first position connecting the first port to second port and a second position connecting the first port to the third port, on first and second working signal pressures applied thereto.

Abstract: A changeover valve (13) connected to a shift valve unit (12) via four oil passages L3-L6, and two pressure regulating valves (14.sub.1, 14.sub.2) are provided. At speed changing when the changeover valve (13) is in a first (right) position, an off-going hydraulic clutch is connected to oil passage L3 to control its pressure drop by the pressure regulating valve (14.sub.1) and an on-coming hydraulic clutch is connected to L5 to control its pressure rise by the pressure regulating valve (14.sub.2). After completion of the speed changing, the changeover valve (13) is switched to a second (left) position. At speed changing when the changeover valve (13) is in the second position, an on-coming hydraulic clutch is connected to L4 to control its pressure rise by the pressure regulating valve (14.sub.1) and an off-going hydraulic clutch is connected to the L6 to control its pressure drop by the pressure regulating valve (14).

Abstract: An upshift control device for an automatic transmission is provided in which the transmission is shifted up by releasing an oil pressure from a first engaging element that has been engaged while applying an oil pressure to a second engaging element that has been released.

Abstract: A control system for an internal combustion engine with an automatic transmission having a torque converter, and a lock-up device. When gear shifting of the automatic transmission is carried out, the output torque of the engine is increased so as to reduce a shock caused by the gear shifting. The engaging force of the lock-up device is changed in response to the increase of the output torque.

Abstract: An apparatus for controlling the pressure of a hydraulically operated frictional coupling device which is released or engaged to achieve a shifting action of an automatic transmission, by first rapidly reducing or increasing the pressure to a predetermined level, holding the pressure at this level for a predetermined time and then continuously reducing or increasing the pressure to complete the shifting action. A learning compensation device is provided to update, by learning compensation, a selected control parameter influencing a pattern of change of the pressure of the coupling device during the shifting action such that the shifting action is achieved in a predetermined manner.

Abstract: A shift control apparatus in a vehicle automatic transmission, where down-shift is carried out from a high velocity step to a low- velocity step.A flatness-aiming control has a common targetted change rate with respect to a turbine rotational speed in the inertia phase, and aims a hydraulic command value for the engaging side element and a hydraulic command value for the releasing side element at flatness in the inertia phase with the passage of time.An initial value setting control sets an engaging side initial value and a releasing side initial value at the beginning of the inertia phase in response to the turbine torque and the turbine rotational speed.

Abstract: A control for shifting from an off-going speed range to an on-coming speed range comprises an off-going range releasing stage, an on-coming range void-stroke-clearing stage, an on-coming range engaging stage and an on-coming range final stage. During the off-going range releasing stage, an off-going engaging element is released in response to a shift command signal. During the on-coming range void-stroke-clearing stage, the engagement-actuation pressure of the on-coming engaging element is set at a predetermined high-pressure for a predetermined time period after the shift command signal is generated, whereby the void stroke of the on-coming engaging element is cleared. During the on-coming range engaging stage, after the completion of the on-coming range void-stroke-clearing stage, the on-coming engaging element is engaged. During the on-coming range final stage, following the on-coming range engaging stage, the on-coming engaging element is engaged completely.

Abstract: In a shift control apparatus in a vehicle automatic transmission, up-shift is carried out from a low velocity step to a high velocity step. When a rotational blow is generated, a controlling device controls the releasing side element of frictional engaging elements in such a target that the releasing side element of frictional engaging elements slips on the mating member with the engaging side element of frictional engaging elements moving for engagement.

Abstract: A control system for an automatic transmission which includes a first speed change unit for executing a predetermined speed change by applying/releasing two of a plurality of frictional engagement elements simultaneously and a second speed change unit capable of executing speed changes in at least two higher and lower stages are connected in tandem. The control system comprises: a speed change abnormality detector for detecting an abnormality in the speed change which is executed by applying/releasing the two frictional engagement elements of the first speed change unit simultaneously; and a first speed change unit speed change inhibitor for inhibiting the speed change, which is executed by applying/releasing the two frictional engagement elements in the first speed change unit, when the speed change abnormality is detected by the speed change abnormality detector.

Abstract: To optimize the application hydraulic pressure of the friction application elements in the transmission mechanism, and to reduce the unnecessary load on each member, the transmission mechanism of an automatic transmission is provided with a plurality of friction application elements which are applied simultaneously in order to achieve the designated gear stage, and hydraulic servos which operate the friction application elements independently. The control apparatus has an information detecting means, an input torque calculating means which calculates the input torque of the transmission mechanism on the basis of this information, an application hydraulic pressure calculating means which calculates the necessary application hydraulic pressure required to maintain the application of each individual friction application element on the basis of the input torque, and a supply means which supplies the necessary application hydraulic pressure to the hydraulic servos of the friction application elements.

Abstract: An automatic transmission of an automotive vehicle is set into a neutral position in response to a command instructing gear shifting of the automatic transmission when release of an accelerator pedal of the vehicle is detected. The automatic transmission has a plurality of speed clutches. The opening of a throttle valve arranged in an intake passage of an internal combustion engine installed on the vehicle is controlled such that the rotational speed of an input side of one of the speed clutches to be selected for the gear shifting and the rotational speed of the one of the speed clutches becomes substantially equal to each other when the automatic transmission is held in the neutral position. The one of the speed clutches is engaged upon detection that the rotational speed of the input side thereof and the rotational speed of the output side thereof becomes substantially equal to each other.

Abstract: Uncomfortable travel of a vehicle due to engine brake actions during the travel of the vehicle in traffic is prevented without using an one-way clutch within a transmission mechanism. An automatic transmission is composed of rotational elements that are braked at the time of establishing low stages, a brake that brakes the rotational elements, and control systems which control the oil pressure of the hydraulic servo in the brake. A band brake that creates differences in application forces, using self-energizing and deenergizing actions, serves as the brake, which is set to have an area in which the oil pressure during the drive is lower than the oil pressure during the non-drive, by setting the self-energizing direction as a direction of rotation of the rotational element during the drive and the deenergizing direction as an opposite direction of rotation of the rotational element during the non-drive.

Abstract: A speed change control system for use in an automatic transmission includes a one-way clutch to be locked and to retain a rotary element in a speed change mechanism for establishing a predetermined gear stage and an engine braking frictional engagement element arrayed in parallel with the one-way clutch and adapted to retain the rotary element, thereby establishing the desired gear stage. The speed change control system further includes a throttle opening detector for detecting the stroke of depression of the accelerator pedal of a vehicle, a downshift detector for detecting a shift to a desired gear stage and an apply pressure controller for controlling the apply pressure of the engine braking frictional engagement element. A speed change decision is made to determine whether a speed change is ended for a predetermined time period, if the throttle opening is in a predetermined region and if the detected shift is a downshift to the desired gear stage.

Abstract: The invention relates to a hydraulic changing device for a multi-ratio vehicle transmission, especially for a commercial vehicle such as a mobile excavator. The hydraulic changing device feeds gear actuator (3, 4) with pressure medium conveyed by a servopump (10). There is a control slide (26) which is acted upon by the effect of a control spring (33), on the one hand, and by a pressure in a low-pressure chamber (23), on the other. The low-pressure chamber (23) is coupled to a low-pressure pump (20) operating in dependence upon the engine speed. The arrangement is completed by a shuttle valve (6) and a leakage valve (5). The pressure prevailing in the low-pressure chamber (23) actuates the control slide (26), against the force of the control spring (23), in such a way that undesired changes from a higher to a lower gear are prevented. The hydraulic changing device, of the invention, is advantageously distinguished by its low structural and design expenditures.

Abstract: A process is proposed for controlling an automatic transmission where changing from one gear speed to another is brought about as a result of a first clutch (11) opening and a second clutch (12) closing. It is further proposed to apply the process to a group transmission.

Abstract: A control system for an automatic transmission having friction coupling elements, at least one of which is locked in 3rd and 4th gears and unlocked in 1st and 2nd gears, includes a first shift valve shiftable between 3rd and 4th gears, and second shift valve shiftable between in 2nd gear and 1st gear in which engine brake available, and a solenoid valve providing control pressure which is selectively directed to these shift valves and cause them to shift so as to lock or unlock the friction coupling elements.

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 controller (100 in FIG. 1) for relieving a gear shift shock in a vehicle, comprising 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: A power train controller and control method are provided for a passenger car driven by a combustion engine and an automatic gear changing transmission. Control sensors detect a current operating state of the passenger car. Three different modes of operation, including sports mode, economy mode, and comfortable mode are selected by the driver. Depending on the selected mode, the automobile transmission is controlled in different shifting patterns as a function of the sensed vehicle operating conditions.

Abstract: A speed change control apparatus for an automatic transmission includes a transmission control unit for controlling gear-changing. The control unit discriminates a fluid temperature/rotational speed zone based on the hydraulic fluid temperature and the engine speed at the start of gear-changing, and detects a time period from the end of dead-stroke elimination of an engagement-side hydraulic clutch to the start of actual gear-changing. In the case that a condition for executing learning correction is satisfied and if a time period from the end of the dead-stroke elimination to the start of the actual gear-changing is longer than an upper limit, the control unit increases a learning-correction time with which a dead-stroke-elimination time for the discriminated temperature/speed zone is calculated. The learning-correction time is decreased if such a time period is shorter than a lower limit.

Abstract: In a shift control method, when a speed ratio of an automatic transmission is shifted from a third speed ratio to a first speed ratio before stoppage of a vehicle, a down shift line 3-1 in a shift pattern is shifted to a high-speed side to initiate shifting under a power-OFF condition. A third brake is released by setting the duty ratio of an electromagnetic valve of the third brake at 0% to establish a free condition (neutral condition) in an output shaft of a second transmission. While the duty ratio of an electromagnetic valve of a second clutch in a first transmission mechanism is set at 0%, the duty ratio of an electromagnetic valve of a second brake is gradually increased, so that the shifting from the second clutch to the second brake is made, and the first transmission mechanism is operatively shifted from the third speed ratio to a speed ratio corresponding to the first speed ratio.

Abstract: A shift control method for executing a shift-up control from an off-going range to an on-coming range comprises an off-going-range releasing stage, an off-going-range controlling stage, and an on-coming-range invalid-stroke-clearing stage. In the off-going-range releasing stage, a pressure command signal is generated to quickly lower the engagement-actuation pressure of the off-going engaging element. In the off-going-range controlling stage, a pressure command signal is generated to control the engagement-actuation pressure of the off-going engaging element in such a way that the off-going engaging element is kept slipping within a predetermined range of input/output rotational speed ratio (=output rotational speed/input rotational speed).

Abstract: An automatic transmission includes the transmission control device which sets a control time upon changeover from the second gear condition to the third gear condition during which the brake device is maintained in the engaged condition until changing to the disengaged condition. The transmission control device also adds a compensating time to the control time upon changeover from the second gear condition to the third gear condition in certain circumstances such as when changeover from the second gear condition to the third gear condition follows operation under the first gear condition, and when change over from the second gear condition to the third gear condition follows vehicle operation under the second gear condition for a period exceeding a predetermined time (e.g., 10 seconds).

Abstract: A hydraulic control system for an automatic transmission includes a hydraulic pump, a pressure regulating valve, a solenoid supply valve, a manual valve, a torque control regulator valve, a control switching valve, a N-D control valve, a 1-2 shift valve, a 2-3 shift valve, a 3-4 shift valve, and a N-R control valve. Accumulators are disposed in conduits to first and seventh friction members for reducing shift shock caused by line pressure and drive pressure fed from fourth and second clutch valves.

Abstract: A shift control system for an automatic is designed to prevent engine racing and clutch tie-up during a clutch-to-clutch shift (clutch switching shift) involving engagement/disengagement of first and second frictional engagement elements. The shift control system includes an engagement force controller for independently controlling both of the frictional engagement elements. A gear ratio calculator continuously calculates a gear ratio r of the transmission and a shift characteristic value calculator calculates a shift characteristic value .alpha. based on changes in the gear ratio between the start of the shift and completion of the shift. A control value calculator calculates a control value .beta., based on the shift characteristic value .alpha. calculated by the shift characteristic value calculator and a shift characteristic value .alpha.I on an ideal gear ratio curve. The control value .beta. is calculated so that the shift characteristic value .alpha. coincides with the shift characteristic value .