Method for operating a drive apparatus and corresponding drive apparatus

Patent metadata

Field	Value
Publication number	US-9988039-B2
Application number	US-201715616312-A
Country	US
Kind code	B2
Filing date	Jun 7, 2017
Priority date	Jun 7, 2016
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

A method for operating a drive apparatus including an internal combustion engine and an electric engine. An output shaft of the drive apparatus can be operatively connected to the internal combustion engine by way of a shifting clutch and can be permanently operatively connected to the electric engine, so that the output shaft is disengaged from the internal combustion engine in a first shifting state of the shifting clutch and is engaged with it in a second shifting state.

First claim

The invention claimed is:

1. A method for operating a drive apparatus comprising:
an internal combustion engine and an electric engine, wherein an output shaft of the chive apparatus can be operatively connected to the internal combustion engine by way of a shifting clutch and is permanently operatively connected to the electric engine, so that the output shaft is disengaged from the internal combustion engine in a first shifting state of the shifting clutch and is engaged with the internal combustion engine in a second shifting state,
wherein, during a starting of the internal combustion engine from a standstill, a clutch adaptation is carried out in an adaptation operating mode, wherein a target clutch torque is adjusted on the shifting clutch in such a way that clutch slip is present, and the internal combustion engine is towed without firing to a first target rotational speed and subsequently towed without firing with a constant target clutch torque to a second target rotational speed, and wherein, after the clutch adaptation, the shifting clutch is completely disengaged, and the internal combustion engine is operated with firing to a synchronous speed, which corresponds to an actual speed of the output shaft.

2. The method according to claim 1 , wherein, with the clutch adaptation from a rotational speed gradient of the internal combustion engine, an actual clutch torque is determined and is compared to the target clutch torque, wherein, in the event of a deviation between the actual clutch torque and the target clutch torque, an adaptation of a clutch characteristic diagram of the shifting clutch is carried out.

3. The method according to claim 1 , wherein, before the second target rotational speed is achieved by the internal combustion engine, fuel injection into the internal combustion engine is suppressed, and then released after the second target rotational speed is achieved.

4. The method according to claim 2 , wherein a linear rotational speed curve is used between the first target rotational speed and the second target rotational speed to determine the actual clutch torque.

5. The method according to claim 1 , wherein the drive apparatus is operated in a normal operating mode and then is only switched into the adaptation operating mode when a certain number of clutch actuations of the shifting clutch is exceeded since the last clutch adaptation or an adaptation request is present, wherein, after starting of the internal combustion engine, during which the clutch adaptation is carried out, there is a switch back to normal operating mode.

6. The method according to claim 5 , wherein the starting of the internal combustion engine in normal operating mode is carried out optionally without firing or with firing, wherein the starting is selected without firing or with &hut based on at least one state parameter.

7. The method according to claim 5 , wherein the internal combustion engine is towed in normal operating mode for the start without firing via the shifting clutch up to the synchronous rotational speed and only then is the fuel injection released.

8. The method according to claim 5 , wherein the internal combustion engine is towed in normal operating mode for the start with firing via the shifting clutch upon released fuel injection until a minimum speed is reached that is less than the second target rotational speed, and subsequently, the shifting clutch disengages, and the internal combustion engine is then operated with firing to the synchronous rotational speed.

9. The method according to claim 1 , wherein, after the synchronous speed is reached by the internal combustion engine, the shifting clutch is completely engaged.

10. A drive apparatus comprising;
an internal combustion engine and an electric engine, wherein an output shaft of the drive apparatus can be operatively connected to the internal combustion engine by way of a shifting clutch and is permanently operatively connected to the electric engine, so that the output shaft is disengaged from the internal combustion engine in a first shifting state of the shifting clutch and is engaged with the internal combustion engine in a second shifting state, wherein the drive apparatus is designed to carry out a clutch adaptation in an adaptation operating mode during a starting of the internal combustion engine from a standstill, wherein a target clutch torque is adjusted on the shifting clutch in such a way that clutch slip is present, and the internal combustion engine is towed without firing to a first target rotational speed, and subsequently towed without firing with a constant target clutch torque to a second target rotational speed, and wherein, after the clutch adaptation, the shifting clutch is completely disengaged and the internal combustion engine is operated with firing to a synchronous speed, which corresponds to an actual speed of the output shaft.

Assignees

• Audi Ag

Inventors

• Brusberg Alexander

Classifications

• B60W2510/0241

  Clutch slip, i.e. difference between input and output speeds · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• B60W2510/0275

  Clutch torque · CPC title

• B60W10/08 Primary

  including control of electric propulsion units, e.g. motors or generators · CPC title

• B60W2710/027

  Clutch torque · CPC title