Zf Friedrichshafen Ag

Jorg Arnold

Valentine Herbeth

Klaus Steinhauser

Georg Mihatsch

Thilo Schmidt

Christian Popp

Gabor Diosi

Christoph Margraf

Andreas Schmidt

Peter Ziemer

Michael Sohler

Rainer Denzler

A method of operating a transmission which is shifted to various operating conditions by engaging shifting elements. At least one of the shifting elements is an interlocking shifting element which has to be engaged to obtain at least one defined operating condition of the transmission during which force flows between an input and an output shaft. When a command is received to engage the interlocking shifting element, a rotational speed of the transmission input shaft is displaced in the direction toward a synchronous rotational speed produced in the engaged operating condition of the interlocking shifting element at least as a function of the rotational speed of the transmission output shaft. When the variation of the rotational speed of the transmission input shaft crosses a predefined rotational speed threshold, the interlocking shifting element is actuated in its engaging direction.

Procedure for operating a transmission device

A method of operating a transmission which is shifted to various operating conditions by engaging shifting elements. At least one of the shifting elements is an interlocking shifting element which has to be engaged to obtain at least one defined operating condition of the transmission during which power flows between an input and an output shaft. When a command is received to engage the interlocking shifting element, a rotational speed of the transmission input shaft is displaced in the direction toward a synchronous rotational speed produced in the engaged operating condition of the interlocking shifting element at least as a function of the rotational speed of the transmission output shaft. When the variation of the rotational speed of the transmission input shaft crosses a predefined rotational speed threshold, the interlocking shifting element is actuated in its engaging direction.

A method of operating a transmission device having gears that are engaged by actuating shifting elements. At least one of the shifting elements is an interlocking shifting element which has to be engaged in at least one gear to transmit drive between an input and an output shaft. When a command is received to engage the interlocking shifting element, a rotational speed of the input shaft is displaced in the direction toward a synchronous rotation speed produced in the engaged operating condition of the interlocking shifting element at least as a function of the rotational speed of the output shaft. The engagement process of the interlocking shifting element from its disengaged operating condition is discontinued if, before reaching the synchronous rotational speed, the variation of the rotational speed of the input shaft crosses a predefined rotational speed threshold without initiating engagement of the interlocking shifting element.

A method for operating a 9-speed transmission which changes operating states by actuating shift elements. At least one of the shift elements is a form-locking shift element, which disengages to implement a defined transmission operating state during which the power flow, between transmission input and output shafts, is present or interrupted. A sensor is associated with the locking shift element. An operating state of the locking shift element can be determined by the sensor. Upon a request to disengage the locking shift element, a disengagement control signal is generated and the locking shift element is actuated in the disengagement direction, depending on the disengagement control signal. The transmission is shifted to a safe operating state, in which at least the transmission output shaft can rotate, when an engaged operating state of the locking shift element is determined by the sensor even though a disengagement control signal was generated.

Procedure for operating a transmission device, particularly a 9-speed-transmission

A method of operating a vehicle drive-train comprising an internal combustion engine and a transmission system functionally connected to the internal combustion engine. The transmission has an interlocking shifting element, one shifting element half of which is functionally connected to the transmission input shaft while the other shifting element half is functionally connected to a transmission output shaft. Upon receipt of a command to change the transmission from a neutral position, in which a force flow through the transmission is interrupted, to an operating condition, in which the force flow through the transmission is produced, the interlocking shifting element is changed to an engaged operating condition. A speed difference between the shifting element halves is brought by varying the speed of the internal combustion engine into a speed difference window within which the interlocking shifting element can be changed to its engaged operating condition.

Method for operating a vehicle drive train having an internal combustion engine

A method of operating a transmission device. At least one of the shift elements is a form-locking shift element. A sensor is associated with the form-locking shift element which can determine an operating state of the form-locking shift element. When a request to disengage the form-locking shift element occurs, a disengagement control signal is generated and the form-locking shift element is actuated in the direction of disengagement, depending on the disengagement control signal. The transmission device is transferred to a safe operating state in which the transmission output shaft can rotate, when an actuating pressure that changes the operating state of the form-locking shift element is determined with the sensor, even though a disengagement control signal was not generated, and/or when the sensor is associated with at least two form-locking shift elements and the form-locking shift elements are subjected to actuating pressure to implement a requested operating state change.

A method of shifting a vehicle drive-train transmission having frictional and interlocking shifting elements which are engageable to obtain various gears. When shifting from a current gear to a target gear, in which the interlocking shifting element is engaged, if after the shift starts it becomes necessary to engage the current gear in the transmission while engaging the interlocking shifting element, a current operating condition of the interlocking shifting element is determined. If the current operating condition of the interlocking shifting element indicates that engagement can be interrupted and the interlocking shifting element can be disengaged, the interlocking shifting element is disengaged. If the current operating condition of the interlocking shifting element indicates that engagement of the interlocking shifting element has to be carried out and the interlocking shifting element engaged, then the interlocking shifting element is engaged and/or the force flow in the transmission device is interrupted.

Method for the operation of a transmission device in a vehicle drive train

A method of determining a fill current value of at least one frictionally engaging shift element of an automatic transmission. The automatic transmission includes a hydrodynamic converter at which a speed ratio arises and an output shaft. In a control sequence, with a stationary output shaft, the speed ratio is influenced by changing a control current, and the fill current value is determined from the progression of the speed ratio arising during the control sequence, in conjunction with the progression of the control current.

Method for determining characteristics of an automatic transmission

A method of operating a transmission of a vehicle drive-train when a gearshift from a current gear toward a target gear has been requested. The transmission having frictional shifting elements and at least one interlocking shifting element. If an actuating electrical current, equivalent to a closed operating condition of the frictional shifting element to be engaged, and an actuating electrical current, equivalent to an open operating condition of the interlocking shifting element to be disengaged, are determined while, at the same time, a closed operating condition of the interlocking shifting element to be disengaged is detected by a sensor, a fault is recognized. If the fault is recognized during a predefined test period, one or more selected shifting elements are disengaged and a force flow in the transmission is interrupted. Alternatively, by disengaging the frictional shifting element to be engaged, the current gear is engaged in the transmission.

Method for the operation of a transmission device in a vehicle drive train when a request is made to change gears

A method of operating a transmission with interlocking and friction shifting elements. In or to carry out a gearshift from a currently gear to a target gear, one shifting element is disengaged and another is engaged, and if to carry out a gearshift an interlocking shifting element has to be engaged, the interlocking shifting element is synchronized by partially closing a friction shifting element, with redundancy in the transmission, only if a current speed of the vehicle is lower than a limit value. To monitor for possible malfunction, actuation of the shifting elements and the driving speed are monitored and if, based on the actuation of the shifting elements, it is concluded that there is a redundancy in the transmission, a stored non-actual driving speed is compared with the limit value and if the stored driving speed is higher than the limit value, the redundancy in the transmission is eliminated.

Method and control device for operating a transmission

A method of operating a transmission device () having a plurality of frictionally engaging shift elements (B, C, D and E) and at least one form-locking shift element (A, F) for implementing different transmission ratios. Upon a requested change in operating state of the transmission device (), the at least one form-locking shift element (A) is transferred into an at least nearly load-free state, during which the form-locking shift element (A) is transferred from an engaged to a disengaged operating state by increasing the transfer capability of at least one frictionally engaging shift element (E), which is not engaged in the power flow of the transmission device () either to represent the present operating state or to represent the requested operating state.

Method for operating a transmission device having a plurality of friction-fit shift elements and at least one form-fit shift element

A method of operating a transmission device comprising friction-locking and form-locking shift elements for obtaining different gear ratios. A shift request for engaging a shift element undergoes a time delay dependent upon an operating state prior to a time of engagement of the shift element. A rotational speed differential between halves of the shift element lies within a rotational speed differential window required for the engagement procedure is assigned to the time of engagement. A gradient of the transmission input speed is ascertained at the time of the shift request, and the actual gradient is subsequently monitored and compared with the gradient that existed at the time of the shift request. If an absolute deviation greater than a threshold value is ascertained, the time delay is changed or an actuation of another shift element to be disengaged is varied such that the deviation is reduced below the threshold value.

Method for operating a transmission device with a plurality of friction-locking and positive-locking shifting elements

A method of operating a vehicle drive-train with an engine and a transmission during a gearshift in which an interlocking shift element is disengaged and a frictional shift element is engaged. Upon a shift command, the shifting time and a transmission input speed are monitored. If the input speed deviates from a synchronous speed equivalent to the gear ratio being disengaged, recognizing disengagement of the interlocking shifting element. If an engaged operating condition of the interlocking shifting element to be disengaged is detected, after the lapse of a time interval beginning with the shift command, a current drive torque of the drive machine is brought by motor actuation to a level that corresponds to a difference between the current transmission input torque and a torque that can be transmitted by the frictional shifting element to be engaged, operating with slip, plus a torque offset value.

Method for operating a vehicle drive train

A method of monitoring an emergency condition in an automatic transmission, with which, by comparing a theoretical with an actual rotational speed, measured on the transmission input side, overlap of the activated emergency condition, with a gear engagement process called for during the normal condition, is prevented.

Method for checking an emergency condition in a transmission system

A method of operating a vehicle drive train having a drive machine, a transmission apparatus having a plurality of shift elements and an output drive. The plurality of shift elements are engaged or disengaged in a power flow for achieving different transmission ratios within the transmission apparatus. The output drive is coupled to a transmission output shaft and the drive machine is coupled to a transmission input shaft of the transmission apparatus. Upon a request to interrupt power flow within the transmission apparatus, between the transmission input shaft and the transmission output shaft, a maximum number of shift elements are transferred to and/or held in an engaged operating state, and the remaining portion of the shift elements are transferred to and/or held in a disengaged operating state with the transmission output shaft being rotatable.

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Immenstaad, Germany

Jorg Arnold