An electronically controlled transmission system includes an engine driven torque converter driving a planetary gear transmission. The torque converter is lockable by a lockup solenoid valve to provide a direct through drive and the planetary gear transmission is shiftable among a plurality of gear ratios by selected operation of solenoid operated valves which control power to clutch- and brake-selected transmission gears. An automatic electronic control provides for a "work" mode of transmission operation wherein a shift control provides for manual shifting over a first set of selected gear ratios and for automatic, speed dependent shifting over a second set of selected gear ratios while torque converter lockup inhibition is provided for both sets of ratios. The automatic electronic control further provides for a "transport" mode of transmission operation wherein the shift control provides for manual shifting over a third set of selected gear ratios and for automatic, speed dependent shifting over a fourth set of selected ratios while automatic torque converter lockup is provided for the upper speeds of each of the gear ratios in the third and fourth sets of ratios. The automatic electronic control still further incorporates hysteresis and time delay automatic shifting to prevent speed related hunting for the proper gear ratios as well as the downshift control to prevent manual downshifting at excessive speeds. A manual override and a hold for holding any automatically selected gear ratio is provided for greater operator control.

Automatic electronic control for a power shift transmission

A lock-up control system is disclosed wherein the lock-up state of a torque converter is temporally released during gear shifting operation in an automatic transmission even if an automotive vehicle is operating in a predetermined lock-up range. A sensor generates an oil temperature compensation signal indicative of the temperature of oil used in the automatic transmission. The time duration of temporary release of the lock-up state is variable with variation in the oil temperature compensation signal.

Lock-up control system for lock-up type automatic transmission

A signal from the speed sensor is extracted at a time period which is later than that for detecting a signal from the engine load sensor by a predetermined amount of time. The speed signal thus obtained is used to decide whether or not shifting of the automatic transmission is necessary, so that any incorrect changeover between two or more shift patterns or shifting between two or more of shift positions in a shift pattern is prevented from being selected due to a delay in the response of the vehicle speed relative to the depression of the accelerator pedal.

Shift control system for a vehicle automatic transmission

A lock-up control system for a lock-up type automatic transmission. A load detector means (220) generates a reference ac­ celeration signal (α′) that indicates a reference acceleration, generates an actual acceleration signal (α) that indicates an actual acceleration of the automotive vehicle, and compares the actual acceleration signal with the reference acceleration signal for generating a first command signal (a L level signal from the comparator 224) when the actual acceleration signal is greater than the reference acceleration signal and generates a second command signal (a H level signal from the compara­ tor 224) when the actual acceleration signal is smaller than the reference acceleration signal. The first command signal is fed to a first vehicle speed comparator means (225) to render same operative. The second command signal is fed to a se­ cond vehicle comparator means (226) to render same operati­ ve. Each of the first and second comparator means compares the vehicle speed signal (V) with a set of reference vehicle speeds (V1L,V2L,V3L; V1H,V2H,V3H) for generating a plurality of patterns of signals that pattern indicate a corresponding plura­ lity of lock-up ranges.

Lock-up type automatic transmission

Valve positioning systems may include one or more components and a controller. Components may include one or more electric-to-pressure output converters, relays, gas supplies, and/or actuators. A controller may adjust a position of a valve by sending a signal. The valve positioning system may individually monitor components and determine the condition of each component being individually monitored. The valve positioning system may determine if a component will fail prior to failure and/or determine if a problem will occur in a component prior to the problem occurring.

Control valve and positioner diagnostics

In an electronic control apparatus of an automatic speed changing apparatus for use in an internal combustion engine of the type wherein the engine is connected with a load through a fluid type torque converter and a multiple stage gear changer, there are provided means for locking-up the torque converter when the speed of the output shaft thereof exceeds a first predetermined speed, means for shifting-up the gear changer to a higher stage when the speed of the output shaft exceeds a second predetermined speed which is higher than the first predetermined speed, and means for shifting-down the gear changer to a lower stage when the speed of the output shaft decreases below a third predetermined speed which is lower than the first predetermined speed whereby effecting automatic speed change control while the torque converter is maintained in the locked-up condition.

Electronic control apparatus of an automatic speed changing apparatus

A retarder control device for a vehicle with an oil-cooled multi-plate disc brake which has solenoid and hand brake valves assembled in parallel with a pneumatic line. A check valve is provided at the pneumatic pressure line for checking oil flow from the solenoid and hand brake valves, and thus the rear brake is manually and automatically operated.

Teruo Minami

Papers

Electronic control apparatus of an automatic speed changing apparatus

Retarder control device

Elektronisches steuergeraet einer automatischen drehzahlaenderungs- oder gangwechselvorrichtung