Robert Boschgmbh

Manfred Schwab

Alfred Muller

Walter Stroh

Gerhard Eschrich

Joseph Sauer

Achim Schreiber

Helmut Mohl

Meinrad Feder

Heinz Leiber

Cornelius Peter

Georg Haubner

Uwe Kiencke

Jurgen Wesemeyer

Rainer Burkel

Gunter Honig

Alfred Schulz

Werner Meier

Hans Schrumpf

Gerhard Heess

Josef Juhasz

Armin Czinczel

Jorg Birmelin

Dieter Schaller

Reference values are stored for various conditions of gear shift operations of a vehicle motor of a particular type and model for various motor speed and load combinations, the reference values having a magnitude characterizing the gear shifting operation, for example the time interval required from the appearance of a gear shift command until the end of slip in a coupling indicates that the gear shift is complete. As the vehicle is driven, actual values of this magnitude are stored and averaged for a predetermined number of shift operations under the same class of condition. Correction values for the pressure of hydraulic fluid of the gear shift control, originally set at zero for all conditions, are determined by comparison of reference values with average actual values and stored. In subsequent driving, the stored correction values are used to control the pressure of the hydraulic medium to maintain a standard of comfort for all shift operations and new average actual values are used from time to time to modify the correction values for compensation of aging effects.

Method of controlling frictionally engageable couplings of an automatic

To control the pressure p of an operating fluid in an automatic transmission (12), the input speed and output speed (n.sub.T, n.sub.out) of the transmission is sensed, and the pressure (p) is so controlled by a control unit (21) that the transmission ratio which is actually coupled by the transmission, in view of the pressure set by the friction bands, is carried out in accordance with a predetermined timing function (i.sub.com), for example as stored in a read-only memory (ROM, 24). Change in shifting characteristics can be obtained, for example, by operator-selected different time-engagement relationships to obtain maximum passenger comfort or maximum acceleration, or intermediate relationships.

Automotive gearshift jolt minimization system

To eliminate the effect of hysteresis when electrical energy is supplied to an electromagnetic positioning element, for example to an electromagnetic valve, upon change in sign of the electrical energy which is provided from a previously occurring change, additional electrical energy is supplied if the change in energy is counter the direction of the magnetization curve. The extent of the additional energy may be at least as great as the gap between the ascending and descending branches of the hysteresis curves (H1, H2), or may be a quantity obtained by experience or measurement if the gap between the hysteresis curves is known or determinable. If the electromagnetic energy applied is in excess of that for reversal of magnetization, it may be applied for a period of time which is just long enough to permit remagnetization of a magnetic portion of the electromagnetic apparatus (11) but not long enough to cause change in a mechanical output thereof.

Method and apparatus to convert an electrical value into a mechanical

To effect soft gear change, without shifting jolts or shocks, the output torque of an automotive vehicular internal combustion engine is controlled in dependence on sensing of an overrunning condition signal derived, for example, by the conjunction of the accelerator pedal being in 'idle' or 'unoperated' condition, and the engine operating at a speed in excess of idling speed. Use of such an 'overrunning condition' signal permits ready control of the engine without requiring additional control elements or systems coupled to the gear change apparatus or to the transmission.

Method of controlling engine operation in an automotive vehicle during

The kickdown function for modifying the operation of an automatic transmission to make the higher power of a lower gear more extensively available is arranged to take place in response to several operating parameters only one of which is the operation of a kickdown switch and the normal gear pattern is restored likewise in response to any one of several parameters. The function is thus more flexibly adapted to driving conditions and avoids the excessive shifting between gear ratios that may result from more rigidly designed kickdown systems.

Control of the shift points of an automatic transmission for temporary

After the gear ratio of an automatic transmission has been increased in response to a braking operation the return to normal operation of the automatic transmission is controlled by logic circuits interconnecting threshold switches operated by the brake pedal and the accelerator pedal and by a read-only memory that stores a maximum engine speed for all values of vehicle speed so that the higher gear ratio is maintained until either the brake is released or the maximum engine speed is exceeded and then the return to normal transmission operation is further delayed until the accelerator pedal is again actuated. In one method, during the period of further delay the gear ratio continues at its raised value. In another embodiment the period of further delay begins with storage of the vehicle speed at the moment and proceeds with control of the transmission to maintain that speed. It is also possible to operate the system so as not to restore normal operation of the transmission after braking when there is only a slight depression of the accelerator pedal.

Method of controlling downshift after braking in automatic transmissions

To control transmission ratio of a continuously variable transmission connected to a combustion engine (e.g., for optimal fuel efficiency of a powered vehicle), effective diameter of pulleys is controlled in response to an electrical signal. A control signal suitable for comparison with hydrostatic pressure values is produced by a computing device based on input signals representing load, speed, and other operating conditions and based further on stored data representing engine characteristics. A control signal is conveniently used to control hydrostatic pressure by means of electromagnetically operated valves. Especially when pulsed valves controlled by digital electric signals are used, a reservoir is used to establish a steady hydrostatic pressure. Such control device is readily adapted to different engines by replacement of stored characteristic data.

Electronic control for a stepless vehicle transmission using a control

The automatic transmission control unit in a motor vehicle furnishes a signal which signifies that motor torque is to be decreased, thereby decreasing jolts or wear on friction elements in the transmission. In response to this signal, the input or output signals of a motor control unit, for example either an ignition control stage or an injection control stage, are changed in such a way that the motor torque will be decreased. Circuits for delaying ignition timing, shortening the pulse width of injection pulses, etc. are disclosed. The present invention is essentially an adapter unit so that the desired decrease in motor torque can be effected with the injection or ignition timing units already present in the motor vehicle.

Apparatus for decreasing jolts during gear shifts in automatic

The hydraulic regulating device for an automatic transmission system in motor vehicles having a plurality of hydraulic couplings, includes a single pressure build-up regulating valve and a single pressure decrease regulating valve and assigned to each coupling a solenoid operated directional control valve having its working port connected to the couplings, its pressure port connected via a switch-on reversing valve to the pressure build-up regulating valve, and its return port connected via a switch-off reversing valve to a return conduit; both reversing valves are controlled according to predetermined pressure levels on the coupling so that in the working position of the switch-on reversing valve the coupling is connected to a stable high pressure and when the coupling process is initiated by reversing the position of the directional control valve, the switch-off reversing valve connects the coupling element to the pressure decrease regulating valve.

Hydraulic regulating device for load shifted gears

In previously known jolt control equipment, it was necessary to know the speed of the turbine of a fluid coupling or hydraulic torque converter driving the automatic transmission. According to the present invention, the turbine speed is assumed to be the same as the impeller or motor speed after the torque transmission through the automatic transmission has been interrupted. Under these conditions, very little slippage in the fluid coupling takes place and the turbine speed is equal to the impeller or motor speed to a sufficient accuracy. The synchronous turbine speed which determines when the jolt control is to be initiated and terminated is computed from the transmission output speed multiplied by the speed ratio between turbine and transmission output in the gear to be engaged.

Method and apparatus for computing motor speeds for initiating and

The signal initiating a reduction of engine torque during gear shift is derived from a monitoring of the engine speed. Specifically, the decrease in torque is initiated when engine deceleration, as determined by the negative speed gradient, exceeds a predetermined value. The torque decrease can, as preferred, take place only if a gear shift occurs, or it may take place independent of gear shift in which case high decelerations caused, for example, by rapid application of the brakes, also cause the decrease.

Method and apparatus for controlling the torque of an internal

The invention pertains to a hydraulic control system for servos in automatic transmissions, which, in a known fashion, utilizes a main pressure valve to regulate the pressure within the control system and further utilizes a converter pressure valve to supply a hydrodynamic torque converter and the lubrication system. The servos (for example, the clutches) utilized in this type of automatic transmissions cooperate with electromagnetically actuated pressure regulating valves have a current-proportional response. These electromagnetic valves are actuated by electronic control signals generated by sensors which monitor various parameters during operation, making previously utilized sensors superfluous. By control of the pressure regulating valves the forward gear, the reverse gear or the neutral gear can be engaged in the simplest fashion. By means of a magnet valve associated with the main pressure valve the levels of pressure may be varied. It is also possible, via simple associated elements, to install an emergency system which during a failure of the electrical system allows the transmission to continue to operate.

Hydraulic control system for servos in automatic transmissions

To supervise a program controlled device which is subject to stray noise or disturbance pulses, particularly microprocessor controlled automotive vehicle electronic systems, a timing circuit is provided responsive to check pulses added to the program and defining a timing interval, the monitoring system distinguishing between disturbance pulses and static defects by supervising the control pulses and, upon failure of the control pulses, generating a program restart or interrupt signal, respectively, which both initiate a new start of the program cycle or, respectively, define a timing interval which, upon failure to sense further control pulses, initiates energization of an emergency switching system. Continuous failure to receive control pulses also can initiate the emergency switching system. To permit start-up, and before control pulses are obtained, a time delay circuit is provided which disables the monitoring system upon switching ON of the program controlled device at least for the time period of one check pulse cycle.

Monitoring system for program controlled apparatus

The initiation and end of the application of a jolt control system to the internal combustion engine during gearshift operations is matched to then-present operating conditions by determining the engine speeds at which the control is to be initiated and ended as a function of the engine speed at the start of the gearshifting. For this purpose, the initial speed is digitalized and used as an address for a storage which contains the desired values. In a second embodiment, the speed at the end of the gearshift is determined and the values read out from storage are speed increment values which are added to the speed at the start of the gearshifting and subtracted from the speed at the end of the gearshift during downshift operations, and vice versa during upshift operations, to determine the engine speeds at which the jolt control is to be initiated and terminated.

Growing community of inventors

Gerlingen, Germany

Manfred Schwab