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

摘要

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.

主权项

1. A method of operating a vehicle drive-train (1) which comprises an internal combustion engine (2) and a transmission (3) that is functionally connected to the internal combustion engine (2) by a transmission input shaft (6), the transmission having a first interlocking shifting element (A) which comprises a first interlocking shifting element half (A6), which is functionally connected to the transmission input shaft (6), the first interlocking shifting element (A) further comprising a second interlocking shifting element half (A7) which is functionally connected to a transmission output shaft (7), the method comprising the steps of:
maintaining a second interlocking shifting element (F) in an engaged condition when the transmission (3) is in a neutral operating condition (“N”); and upon receiving a command to change from the neutral operating condition (“N”), in which a force flow in the transmission (3) is interrupted, to an operating condition in which the force flow to an output of the transmission (3) is produced, initiating engagement of the first interlocking shifting element (A) by:
altering a rotational speed (n_A6) of the first interlocking shifting element half (A6) of the first interlocking shifting element (A) by varying a speed (n_2) of the internal combustion engine (2), andbringing an actual rotational speed difference, between the first and the second shifting element halves (A6, A7) of the first interlocking shifting element (A) into a speed difference window, within which the first interlocking shifting element (A) is changeable to the engaged operating condition, and engaging the first interlocking shifting element (A), when the actual rotational speed difference is within the speed difference window, to produce the force flow in the transmission (3).