Abstract: A controller for an automatic transmission which reduces wear of frictional engagement elements and shortens gear change time even when a gear change jump is made. The controller of the present invention includes a first hydraulic servo to which oil is supplied to make a gear change jump, a second hydraulic servo to which oil is supplied to make a gear change to an intermediate gear stage, a limited supply oil circuit having an oil flow limiting element, a quick supply oil circuit bypassing the oil flow limiting element and a pressure governor for regulating a line pressure to supply oil at a controlled pressure to the quick supply oil circuit. An oil path switching valve switches oil supply, to the first hydraulic servo or the second hydraulic servo, between the limited supply oil circuit and the quick supply oil circuit.

Abstract: An electronic and hydraulic system of a five speed automatic transmission adapted to establish five forward and one reverse gear ratios by way of effecting selective engagement and disengagement of friction elements comprises an oil pump for producing a pressurized working fluid, a manual selector valve manually operated for distributing the working fluid to forward and reverse fluid lines, first to fourth shift valves for directing the working fluid to one of the friction elements, first to fourth solenoid valves associated with the first to fourth shift valves, respectively, for controlling positions of the shift valves in correspondence to a vehicle speed and a throttle opening degree, second to fourth speed valves each position-controlled by the first to third shift valves to change flow path of the working fluid and an overdrive unit valve position-controlled by the fourth shift valve.

Abstract: A hydraulic control system of an automatic transmission for an automotive vehicle includes a hydraulic pump, a pressure regulating valve, a torque converter, a converter clutch, first, second and third solenoid valves, first through eighth friction elements, second and third speed clutch valves, a band valve and a manual value. The pressure regulating valve varies a hydraulic pressure when shifting, and the converter clutch regulator valve actuates a damper clutch to improve transmission efficiency of the torque converter. The first, second and third solenoid valves supply or obstruct the supply of hydraulic pressure from the pressure regulating valve to a respective one of a first, second and third clutch shift valve to displace valve spools of a respective one of the first, second and third clutch shift valves. The second speed and third speed clutch shift valves as well as the fourth speed band valve, selectively supply hydraulic pressure to the friction elements to perform shifting.

Abstract: A hydraulic control system for an automatic transmission of automotive vehicles is provided. The hydraulic control system includes a pressure source, a plurality of solenoid valves, and a plurality of directional control valves. Each solenoid valve selectively supplies and release hydraulic pressure to and from one of frictional element of a power train of the automatic transmission according to a given schedule of transmission operation for establishing a given gear ratio. The directional control valves are interposed between the frictional elements of the power train and the solenoid valves, respectively.

Abstract: The present invention relates to an adaptive control method for an automatic transmission. The method includes the steps of:(a) commanding a predetermined clutch to fill in accordance with a plurality of clutch fill parameters;(b) determining the actual time to completely fill the clutch;(c) comparing the actual fill time with a predetermined fill time; and(d) adjusting at least one of the plurality of clutch fill parameters in response to the comparison in order to modify the clutch fill period during subsequent shifts to the predetermined clutch. Accordingly, the present invention adapts future shifts based on past shifts to improve the shift quality of the transmission.

Abstract: An automatic transmission control system has first and second hydraulic circuits leading to a low/reverse brake and a reverse clutch, respectively, which perform supplying and discharging of hydraulic pressure to the low/reverse brake and reverse clutch, respectively, so as to lock and unlock them. The first circuit is provided, from the upstream end, with an orifice for restraining hydraulic pressure, an accumulator disposed downstream from the orifice for pressure accumulation, and a switching valve for switching supply and discharge of the hydraulic pressure. The second hydraulic circuit is provided, from the upstream end, with a switching valve for switching communication of the first hydraulic circuit between the orifice and switching valve with the second hydraulic circuit and communication of the first hydraulic circuit upstream from the orifice with the second hydraulic circuit.

Abstract: The present invention is directed to methods and systems for improving the operation of a transmission for an automotive vehicle, and in particular the transmission as installed by the original automobile manufacturer. The methods and systems of the present invention modify the original hydraulic fluid circuits of the automotive transmission provided by the automobile manufacturer to enable the transmission to select any available ratio at any time, and to enable the transmission to produce quick applies and releases for racing applications with only minimum ratio sharing or overlap.

Abstract: A transmission control wherein modulating solenoid valves provide for continued governor and accumulator trim boost in the event of a malfunction in either the electrical or the hydraulic system. The transmission control provides redundancy to permit continued operation in the event one of the modulating solenoid valves fails. A single interlock valve is employed to prevent the two modulating solenoid valves from pressurizing the governor and the trim boost circuits when the transmission is operating in the reverse drive range.

Abstract: A hydraulic control system of the present invention is provided for improving a responsiveness to a speed change by compleating the speed chang with a torque pressure control hydraulic pressure after initiating the speed change with the drive hydraulic pressure. The hydraulic control system includes an oil pump for generating hydraulic pressure, a pressure regulating valve for regulating the hydraulic pressure to be proper pressure for reverse and drive, five friction elements which receive the hydraulic pressure for drive in accordance with operation of a manual valve, two friction elements which receive the hydraulic pressure for reverse in accordance with operation of the manual valve, first and second shift control parts having at least two shift valves, respectively, to supply the hydraulic pressure to the friction elements, and a torque control hydraulic pressure regulating part for supplying a torque control hydraulic pressure to the first and second shift control parts.

Abstract: A control system for an automatic transmission, includes a first hydraulic servo adapted to be fed with oil for effecting a shift to a target gear stage; a second hydraulic servo adapted to be fed with the oil for effecting a shift to the target gear stage; a limit oil feed circuit formed through an oil limit flow limiting device; a quick oil feed circuit bypassing the oil flow limiting device; and an oil passage switch for switching and connecting the limit oil feed circuit and the quick oil feed circuit to the first hydraulic servo and the second hydraulic servo. The oil passage switch feeds oil from the quick oil feed circuit to the first hydraulic servo and the second hydraulic servo, when the engine load is high, and feeds oil from the limit oil feed circuit to at least the first hydraulic servo when the engine load is low.

Abstract: A control system for a shift-by-wire automatic transmission, comprises: a first range changing valve for having an input port switched to communicate with a first output port and a second output port; a second range changing valve for causing the first input port connected with the first output port to communicate with two range ports selectively and for causing a second input port connected with the second output port to communicate with at least another of the range ports selectively; and a drive mechanism for switching and operating the first and second range changing valves. Further comprised are: a fail detector for detecting a failure that either of the first range changing valve and the second range changing valve fails to be switched; and a fail controller for outputting an instruction signal to the drive mechanism to change the range by actuating the switchable one of the range changing valves if the fail detector detects the failure.

Abstract: A vehicular automatic transmission and control system therefor includes an automatic transmission including a planetary gear unit and a plurality of friction elements for connecting the components of the planetary gear unit selectively to rotary members or stationary members; a hydraulic control unit for selectively switching and controlling oil pressures to be fed to the friction elements; and an electronic control unit for outputting a signal indicating the running state of a vehicle to control the feed of the oil pressures to the friction elements.

Abstract: A hydraulic control for an automatic transmission is composed of a gear shift mechanism having first and second frictional engagement elements, a hydraulic control unit for the engagement elements, and an electronic control unit for the hydraulic control unit. The first element is engaged to achieve a first speed stage and the second element is engaged to achieve a second speed stage faster than and closest to the first speed stage. The hydraulic control unit has a first directional control valve for switching the feeding and discharge of hydraulic pressure between the first and second engagement elements, responsive to a first solenoid signal from the electronic control unit. A second directional control valve is adapted to be switched by a second solenoid signal from the electronic control unit to achieve a third speed stage yet faster than the second speed stage. The first engagement element has a discharge line connected to a drain line via the second directional control valve.

Abstract: A countershaft type power transmission has a plurality of hydraulically actuated synchronizers which are selectively operable to establish the gear ratios in the transmission. Each synchronizer is effective to control one or more ratios and is positionable between neutral positions. A hydraulic control system is provided to control the movement of the synchronizers and to hydraulically force each synchronizer to neutral when it is not called upon for ratio establishment.

Abstract: A multiple stage automatic transmission includes a main transmission mechanism, a sub-transmission mechanism connected with the main transmission mechanism to for introduction of a torque therefrom, and a frictional element connected with the sub-transmission. The engaging force of the frictional element is changed at least by two steps in accordance with a shift mode without changing a hydraulic pressure applied for actuating the frictional element. A shift shock, therefore, can be obviated.

Abstract: A control system for a shift-by-wire automatic transmission, comprises: a first range changing valve for having an input port switched to communicate with a first output port and a second output port; a second range changing valve for causing the first input port connected with the first output port to communicate with two range ports selectively and for causing a second input port connected with the second output port to communicate with at least another of the range ports selectively; and a drive mechanism for switching and operating the first and second range changing valves. Further comprised are: a fail detector for detecting a failure that either of the first range changing valve and the second range changing valve fails to be switched; and a fail controller for outputting an instruction signal to the drive mechanism to change the range by actuating the switchable one of the range changing valves if the fail detector detects the failure.

Abstract: A control system is provided for servo hydraulic pressure in an automatic transmission having planetary gear mechanisms. First and second frictional engagement devices, whose servo pressures are reversed in feed/drain relationship between desired two high speed stages, are controlled by a shift valve and a directional control valve. The shift valve is switched by a first solenoid. The directional control valve is interposed in a servo hydraulic pressure feed/drain line communicating the shift valve with the first frictional engagement device and is controlled by a second solenoid. The first and second solenoids are controlled by an electronic control unit in accordance with a shift position detected by a detector, whereby the timings of feed or drain of the servo hydraulic pressures to or from the first and second frictional engagement devices are changed by predetermined relative amounts, respectively.

Abstract: A transmission control has a redundancy control for upshift and downshift control of friction torque transmitting devices in a power transmission. The control solenoid valves providing for continued governor and accumulator trim boost in the event of a malfunction, in either the electrical system or the hydraulic system, which affects the governor pressure schedule. A reverse control signal, from a manual valve, is effective to remove the malfunctioning solenoid valve from effective operation in the control.

Abstract: A shift control system comprises duty solenoid valves by which engagement pressure of one friction element to be released and that one of the other friction element to be engaged can be controlled individually.