Method for operating a drive unit for a hybrid vehicle

Abstract

Method for operating a drive unit for a hybrid vehicle, wherein the drive unit comprises a drive assembly (3) with an internal combustion engine (1) and an electrical machine (2) and a transmission (5) having a plurality of gearboxes (6, 7) connected between the drive assembly (3) and an output (4). The electrical machine (2) is coupled via a planetary gear unit (10) to an input shaft (8) of a first gearbox (6) and an input shaft (9) of a second gearbox (7) connected in parallel with said first gearbox (6). Therein the internal combustion engine (1) can be coupled by means of a friction-fitting decoupler (11) to the input shaft (8) of the first gearbox (6) and when the decoupler (11) is closed is coupled together with the input shaft (8) of the first gearbox (6) to the same element (15) of the planetary gear unit (10) A friction-fitting or form-fitting bypass shifting element (12) interacts with the planetary gearbox (10) in such a manner that, when the bypass shifting element (12) is engaged, a rotationally fixed connection exists between the electrical machine (2), the input shaft (8) of the first gearbox (6) and the input shaft (9) of the second gearbox (7) and thereby there is necessarily equality of rotational speed between the same, whereas when the bypass shifting element (12) is disengaged said rotationally fixed connection and said necessarily equal rotational speed for not exist. On execution of a shift under load, shortly before the engagement of an interlocking shifting element to be closed for the shift under load, the friction decoupler (11) is shifted to slipping mode in order to decouple the inertial mass of the internal combustion engine (1).

Description

technical field [0001] The invention relates to a method for operating a drive unit for a hybrid vehicle. Background technique [0002] A drive unit for a hybrid vehicle is known from DE 10 2006 059 591 A1, wherein the drive unit comprises a drive unit with an internal combustion engine and an electric machine and a transmission connected between the drive unit and an output. The transmission is designed as a dual clutch transmission and includes a plurality of sub-transmissions. The electric machine of the drive of the drive unit is coupled via a planetary gear to an input shaft of a first sub-transmission and to an input shaft of a second sub-transmission parallel to the first sub-transmission. The internal combustion engine can be coupled via a friction-locking release clutch to the input shaft of the first sub-transmission and, with the release clutch engaged, the internal combustion engine can be coupled directly to the input shaft of one of the sub-transmissions. [...

AI Technical Summary

Problems solved by technology

[0004] When, in these drive units known from the prior art, a power shift from the current gear of one sub-transmission to the target gear of the other sub-transmission is to be performed, undesired engagement shocks can occur which are felt for uncomfortable

Images