Zf Friedrichshafen Ag

Zahnradfabrik Friedrichshafen, Ag.

Knorr-bremse Systeme Fuer Nutzfahrzeuge Gmbh

Friedrichshafen Ag

Rainer Petzold

Mario Steinborn

Franz Bitzer

Peter Herter

Joachim Staudinger

Rupert Kramer

Norbert Wiencek

Friedbert Roether

Robert Ingenbleek

Markus Deeg

Martin Miller

Ulrich Reith

Stefan Veittinger

Roland Mair

Thomas Jäger

Werner Wolfgang

Johannes Kemler

Marcus Gansohr

Andreas Wolf

Wolfgang Gröner

Reinhard Mertinkat

Gerd Sauermann

Klaus Hensinger

Norbert Lemp

Walter Fritz

A method of controlling and regulating a transmission brake which, for the purpose of synchronization, determines a target rotational speed of a shaft to be synchronized on the basis of an actual rotational speed of a transmission shaft, and controls a transmission brake such that the determined target rotational speed is set for the shaft that is to be synchronized. The transmission brake also carries out additional functions. These functions require no, or only minimal, additional hardware complexity in a cost-neutral way, but considerably increase the functional and practical value of the transmission brake. The comfort and speed of shifting operations, the protection or, as the case may be, the detection of error states in sensors, a clutch, a main clutch or a motor control are improved, and undesirable transmission states avoided. It is also possible to account for and influence other conditions, such as the operation of ancillary devices.

Method for broadening the function of a transmission brake

A method of controlling an automatic geared transmission of a vehicle drive train. The transmission is linked, on the input side, to a hybrid drive which comprising an engine and an electric motor and, on the output side, to an axle drive and wheels. During vehicle stand still with the engine and/or electric motor operating and a disengaged drive train, rolling of the motor vehicle is prevented, or at least limited, by shifting the transmission. When the automatic geared transmission is in the neutral position (G=N), a safety function is activated to avoid uncontrolled rolling of the vehicle in which actuation of shift operating elements, the throttle and the brake pedal, as well as the rolling speed, are captured by sensors and in which, when the drive operating elements (shift operating element x=0, throttle x=0, brake pedal x=0) are not activated, a starting gear is engaged once a predetermined limiting speed (v&#x3e;v) is exceeded.

Method for controlling an automatic geared transmission

A through-connection clutch, for transferring torque between a motor and transmission of a vehicle, which has a friction clutch and a form-locking clutch. The form-locking clutch is disposed radially within the friction clutch, and the clutches can be actuated independently of each other. To minimize the required installation space, the through-connection clutch can be activated flexibly, but is still inexpensive to produce and ensures low-wear yet safe and comfortable torque transfer in a drive train of a vehicle. A pressure plate of the friction clutch and a form-locking element of the form-locking clutch are concentric, rotationally fixed together, and movable toward one another, and can be actuated via an actuation unit, which is rotationally decoupled from the pressure plate and the form-locking element. Depending on the operating situation, the friction clutch and/or the form-locking clutch is selectively activated one or more times.

Through-connection clutch and method for the actuation thereof

A method is proposed for controlling a through-connection clutch of a vehicle, in which an interlocking portion of the clutch is opened when the drive-train is virtually free from torque, a shifting operation is then carried out, and after the shifting operation the clutch is closed again. According to the invention, the torque transmitted by the interlocked connection in the clutch is influenced by controlling the motor in order to produce a torque-free condition at the interlocked connection in the clutch, in such manner that the interlocked connection is pre-stressed before the torque-free condition has been reached and separated immediately only when the torque-free condition is reached.

Method for controlling a rolling or coasting function of a vehicle

A method for determining the output speed (N_AB) of a manual transmission of a motor vehicle. The output speed (N_AB) is calculated during a period of a shifting operation in which the current gear is disengaged and the new gear has yet to be engaged. The calculated output speed (N_AB) is used for controlling adjustment of the speed of the transmission input shaft (N_EG) to the speed of the transmission output shaft, or the calculated output speed (N_AB), is used for checking the plausibility of a value of the output speed (N_AB) as determined by the sensors.

Method for determining the output rotational speed of a manual transmission

A method of determining and reducing vibrations caused by a clutch () in a drivetrain () of a motor vehicle, in which the disturbing vibrations are detected by a control and regulating unit aided by suitable sensors and, if predetermined limit values are exceeded, at least one device is actuated by the control and regulating unit in such manner that the disturbing vibrations are completely eliminated or at least reduced in amplitude. At least one torque sensor () is used to detect the occurrence of vibrations in the drivetrain () and the torque sensor () is used to determine vibration amplitude.

Method and device for determining and dampening juddering vibrations of a drivetrain

A method and a device for controlling a clutch, for example an automatic friction clutch forming part of a drive train of a motor vehicle, for a torque transfer between an engine and a transmission, with the clutch having significant clutch way points assigned to it. For achieving the operational readiness of the clutch over the shortest possible time period, whereby an accurate clutch adjustment is still guaranteed, a clutch way point coordinate system is monitored by checking the point of engagement of the clutch, established through a learning process and having at least a relevant clutch way point for the starting procedure. In case of any recognized change(s), the clutch way point is suitably corrected or otherwise used as is.

Method and device for controlling a clutch by clutch way point coordinate system

A method of controlling a multi-step transmission which is connected, via a friction clutch or by a torque converter, to a engine, and, via an axle, to wheels such that when the vehicle is stationary, the engine is running and the drivetrain is disengaged, rolling of the vehicle is prevented or restricted by a shift of the multi-step transmission. The method to prevent rolling includes the step that when the multi-step transmission is in neutral, a safety function is activated, in which actuation of a shift operation element, the accelerator and brake pedals and the current rolling speed are detected by sensors and, if the driving operation elements have not been actuated, then if a predefined rolling speed limit is exceeded, the friction clutch is disengaged if necessary, a starting gear is engaged and the friction clutch is engaged.

Method for controlling an automated step-by-step variable speed transmission

A method for actuating a clutch () of a drivetrain of a motor vehicle such that, when the motor vehicle is rolling downhill with the accelerator pedal not being actuated and when the motor vehicle is coasting on level ground with the accelerator pedal not being actuated, a clutch position of the clutch () is determined as a function of a rotational speed difference between an input speed of a transmission () of the drivetrain and an idling speed of a power engine () of the drivetrain. The method includes the steps of determining the clutch position from the rotational speed difference between the transmission input speed and the power engine idling speed and correcting the clutch position using at least one parameter that depends on acceleration of the motor vehicle.

Method for actuating a clutch of a drivetrain

A clutch system for producing and interrupting a force flow between the engine and transmission of a motor vehicle, with a clutch, which is disengaged unless actuated, and one or more valves, which regulate the flow of pressure medium and which are electrically actuated by a control and regulation unit. If there is electrical failure while driving and when a gear is engaged or when the vehicle is stationary, the engine is running and a transmission gear is engaged, unintended clutch engagement is prevented. The valves are designed such that if there is a failure of the voltage supply and consequently also of the actuation of the valves by the electronic control and regulation system, the operating condition of the clutch existing at the time of failure, namely the disengaged or engaged operating condition, remains as it is.

Clutch system

A method of monitoring a hydraulic or pneumatic transmission control system, which comprises a pressure supply unit with a conduit directing a pressure medium under a supply pressure, and an actuating member for a clutch control element of a friction clutch. The actuating member has a pressure space which can be connected by a clutch control valve to the conduit, and in which the supply pressure is determined by a pressure sensor that can be connected to the conduit. The method includes the steps of determining the supply pressure by the pressure sensor, given that briefly opening the clutch control valve produces a pressure increase and/or a pressure gradient of the control pressure in the pressure space, and the currently existing supply pressure can be calculated from the control pressure, the pressure increase and/or the pressure gradient.

Procedure for controlling a hydraulic or pneumatic transmission control unit

A method of controlling an automated friction clutch arranged in a drivetrain of a motor vehicle in the force flow, between a motor and transmission, and the automated friction clutch is designed to be passively engaged by spring pressure and can be disengaged and engaged by a controllable clutch actuator. The automated friction clutch is provided with a path sensor for detecting the clutch actuator travel such that during the operation of the motor a current key point of a torque characteristic, provided for controlling the friction clutch, is determined and used for adapting the torque characteristic. With the friction clutch engaged and without the clutch actuator exerting any force, several values of the actuator travel are determined at intervals from which a current engagement point, close to the actual engagement point of the torque characteristic, is determined and with which the torque characteristic is adapted.

Method for controlling an automated friction clutch

A method of controlling an automated friction clutch in a drivetrain of a motor vehicle between a drive motor and a manual transmission. During clutch actuation, at least one operating parameter of the friction clutch is detected by a sensor and from variation of the operating parameter at least one adaptation parameter is derived for correcting a control parameter of the associated clutch control element. To obtain information about variation of the clutch release force and to improve the control of an associated clutch control element, the friction clutch is fully disengaged with constant control or actuation of the clutch control element. During the disengagement process, the release travel path is determined as a function of release time, and from the time variation of the release travel path, a characteristic value is determined which is used to determine an adaptation parameter for correcting the control parameter of the clutch control element.

A clutch actuator (), as well as a method for operating a clutch (), between the drive motor and the transmission () of a motor vehicle. The clutch actuator includes a cylinder with a piston () and an actuator (), such that a clutch release bearing (), arranged co-axially to the central axis of the clutch, may be operated to apply an axial pre-tensioning force on the clutch release bearing and conduct an operating medium into the clutch actuator for axially displacing the piston and/or the clutch release bearing. To simplify a clutch actuator of this type and enhance its utilization, the clutch actuator is configured and used for generating the pre-tensioning force.

Clutch actuator and method for actuating a clutch

A hydraulic or pneumatic control device for an automated shift transmission including actuating devices with actuating cylinders () having pressure spaces (). The pressure spaces () of the actuating cylinders () can be connected by a respective control valve () to a pressure line (), which can be selectively connected to or cut off from a main pressure line () by a main shut-off valve (). At least one additional main shut-off valve () is arranged in parallel with the first main shut-off valve () between the main pressure line () and the pressure line () to improve the control characteristics and increase the operational reliability.

Growing community of inventors

Friedrichshafen, Germany

Rainer Petzold