Zf Friedrichshafen Ag

Zahnradfabrik Friedrichshafen, Ag.

Norbert Wiencek

Rainer Petzold

Bernd Doebele

Bernd Döbele

Mario Steinborn

Thomas Jäger

Peter Herter

Andelko Vesenjak

Ramon Cordt

Bernd D&ouml;bele

Walter Fritz

A method of operating a drive-train which comprises a drive aggregate, a transmission and a starting clutch connected between the drive aggregate and the transmission such that during rolling and coasting, in a thrust operation, the drive-train is operated in such manner that a target value for the position of the clutch is determined as a function of a transmission input speed. The target value for the position of the clutch is compared with a corresponding actual value and, on the basis of the deviation between the target and actual values, a control parameter is generated for adjusting the clutch. The target value for the position of the clutch, during rolling and coasting, is determined in such manner that for a defined value of the transmission input speed, a target value is determined for the position of the clutch when rolling which is different from that determined when coasting.

Method for operating a drive train

A shift control method for an automated gearshift transmission arranged in a drivetrain of a motor vehicle, between a drive motor and an axle drive, which is provided with unsynchronized gear clutches and whose input shaft can be connected to the driveshaft of the drive motor by an automatically controllable separator clutch such that, for an upshift, the synchronization of the target gear takes place with the separator clutch disengaged by setting a substantially constant braking torque at a transmission brake in driving connection with the input shaft. In order to speed up the shift sequence, without additional design measures, as the input speed of the gear clutch of the target gear approaches its output speed, to complete the synchronization, the separator clutch is partially engaged and then disengaged again substantially simultaneously as the transmission brake is released.

Shift control method in an automated manual transmission

A device for reducing the drop in tractive force during the gear shifting phase of an automatic transmission comprising an automatically actuated drive clutch. The device comprises a rotary storage device that can be coupled, if necessary via two transmission ratio steps () that are each assigned a friction clutch (), to the output shaft of the transmission or, if the transmission has a downstream range group, to the output shaft of the main friction transmission. Only one of the two friction clutches () can be activated at any time, and a step up ratio can be achieved and the rotary storage device can be loaded with one of the transmission ratio steps (). A step down ratio can be achieved and energy can be released from the rotary storage device to the output shaft using the other transmission ratio step ().

Device for reducing the drop in tractive force

A method for shifting gears of an automatic transmission of a vehicle, by way of primarily form-locking shifting elements, while driving with or without utilization of a clutch depending on a decision made by a decision device which, in the presence of certain basic conditions, causes disengagement of a starting gear without disengaging the clutch, and subsequently reads in data about the size and the progression of a quantity correlating closely with the rotational speed of an output shaft of the automatic transmission and, with inclusion of this data, determines the shifting mode for engagement of the target gear.

Method for carrying out a shift of gears of an automatic transmission

An automatic transmission control method in which at least one of a starting clutch, a clutch coupling and transmission elements, for selection as well as engagement and disengagement of a gear step, are determined as a function of respectively existing variables representing the driving situation as well as the driver's wishes can be activated by actuators which are controlled by a control and regulation device. The method comprising the steps of collecting and normalizing the input variable into standard input variables; weighting with weighting factors and summarizing; converting the weighted input variables into intermediate variables; selecting a specific range of values which represents a specific shifting sequence; and implementing the shifting operation.

Method for controlling an automatic transmission

The present invention relates to a method for overcoming tooth butt conditions (ZaZ) when engaging gears in transmissions. A sensitive adjustment of the clutch to apply torque for rotating the drive shaft of the transmission in order to overcome tooth butt conditions has certain limits because of the proportion of the power required and desired for making said sensitive adjustment. This may cause unpleasant jerking of the vehicle or a clearly audible locking noise of the involved positively connected elements and undesired mechanical stress to said elements. The method according to the present invention provides a remedy due to the fact that during each shifting process, regardless of the occurrence of a tooth butt condition, the clutch is brought into a position allowing minimum predetermined torque transmission to the drive shaft of the transmission, and this torque is supported on a transmission brake, which is often already available. Due to its substantially smaller size, the transmission brake can much more quickly and accurately adjust a desired net torque curve and torque progress on the drive shaft of the transmission when a tooth butt condition occurs and thus make it significantly easier to overcome the tooth butt condition.

Method for overcoming tooth butt conditions when engaging gears in transmissions

A method and a device for controlling starting, driving and shifting processes of a motor vehicle with a drive motor () and a gearshift (), which can be brought into effective drive connection with one another using a starting and shifting clutch (), with a clutch actuation device () as well as with a control apparatus () which stands in connection with a power element of the same for controlling the power of the drive motor (), and which is connected using signal engineering with sensors () which ascertain an accelerator deflection angle (A), a motor rotational speed (C) and a transmission input shaft rotational speed (E).

Method and device for the control of starting driving or switching processes on a motor vehicle

A method for detecting a rotational direction of the secondary side of a starting clutch in a motor vehicle string comprising the steps of determination of the primary speed of rotation of the primary side and of the secondary speed of rotation of the starting clutch. If the secondary speed of rotation is greater than the primary speed of rotation, an actuator operates in a closing direction, whereby the degree of closure of the starting clutch is adjusted to be dependent upon the acceleration of the secondary speed of rotation. A specified value for a rotational speed of the driving motor is produced which represents the secondary speed of rotation. To the extent that this value exceeds the value of the primary rotational speed, the rotational speed of the motor is regulated to the specified value. If the primary and secondary rotational speeds are equivalent within a preselected period of time, then detecting the same rotational direction for the primary and secondary sides of the starting clutch. If the rotational speed of the primary side of the starting clutch lies below the idling speed of rotation, detecting different rotational directions for the primary side and the secondary side of the starting clutch.

Procedure for the detection of the direction of rotation and secondary side of a starting clutch

A method for controlling the gear release in an automated multi-speed drive in a vehicle drive with a drive motor and a separating clutch positioned between the drive motor and the multi-speed drive that the events 'application of a shifting power' and 'opening of the separating clutch' are determined dependent on reaching certain vehicle accelerations (a, a). The vehicle acceleration (a) decreases at the beginning of the shifting process due to the reduction of the fuel injection quantity (EM) supplied to the drive motor.

Method for controlling gear definition in an automated stepped gearbox

Control of shiftable clutches by a clutch control signal that is a function of the difference between the actual and desired engine rotational speeds and of the gradient of the actual engine rotational speed and wherein the clutch control signal values are generated by the employment of a set of clutch engagement and disengagement speed curves.

Method for controlling disengageable clutches for starting and for shifting variable-speed gears in automobiles

A device for the control of an automatic motor vehicle clutch is arrayed between an engine and a geaar box and acts primarily as a start-up clutch. A control device receives an electric signal coming from an electronic control device and transforms it into a control quantity for an actuator which engages and disengages the clutch. The engagement of the clutch at start-up occurs with a basic clutch-in speed dependent upon the positioning of the gas pedal and initiated by this positioning and is determined as an electric signal by an electronic control device. For this purpose, a characteristic curve which was determined specifically for the engine is stored in the memory of the electronic control device so that in dependence on the displacement angle of the gas pedal the basic clutch-in speed can be determined very quickly and in a simple manner. It is possible to further improve the quality of the clutch-in process by means of correction factors which are multipliers for the basic clutch-in speed. The highest requirements of a clutch are satisfied when, shortly before reaching the point of synchronization, the clutch is displaced once more in direction of disengagement, whereby the moment of disengagement as well as the disengagement speed are likewise determined by characteristic curves.

Growing community of inventors

Hagnau, Germany

Norbert Wiencek