METHOD FOR OPERATING A MULTI-AXLE DRIVE DEVICE AND CORRESPONDING MULTI-AXLE DRIVE DEVICE

Abstract

A multi-axle drive device and method for operating a multi-axle drive device. The multi-axle drive device is provided with a synchronization clutch present in an operational connection between a first output shaft and a connecting shaft and at least one disconnecting clutch present in an operational connection between the connecting shaft and a second output shaft. The synchronization clutch and the disconnecting clutch are opened in a first operating state and closed in a second operating state. At the same time, with an intended change from the second operating state to the first operating state, the synchronization clutch is maintained at least partially opened and the separation clutch is maintained closed, so that, when a first operating mode is carried out, the disconnecting clutch is opened, and when a second operating mode is carried out, the synchronization clutch is closed again.

Claims

1-10. (canceled)

11. A method for operating a multi-axle drive device, the multi-axle drive device having a synchronization clutch arranged in an operational connection between a first output shaft and a connecting shaft, a disconnecting clutch arranged in an operational connection between the connecting shaft and a second output shaft, wherein each of the synchronization clutch and the disconnecting clutch is configured to be opened in a first operating state and closed in a second operating state, the method comprises: switching from the second operating state to the first operating state by opening the synchronization clutch at least partially, and maintaining the disconnecting clutch in a closed state; conducting one or more operations in a first operation mode by opening the disconnecting clutch; and conducting one or more operations in a second operation mode by closing the synchronization clutch.

12. The method according to claim 11, wherein the step of conducting one or more operations in the first operation mode is initiated when the value of at least one of a traction variable or a variable of driving dynamics is equal to or greater than a threshold value.

13. The method according to claim 11, wherein the step of conducting one or more operations in the second operation mode is initiated when the value of a traction variable is less than a threshold value.

14. The method according to claim 11, wherein initiation of at least one of the step of conducting one or more operations in the first operation mode or the step of conducting one or more operations in the second operation mode is based on a traction variable, and wherein the traction variable comprises at least one state variable of a motor vehicle.

15. The method according to claim 11, wherein execution of the method is based on a variable, the variable comprising at least one of a traction variable or a state variable, and wherein the variable is or is based on at least one of a transverse acceleration value, a wheel slippage value, or a yaw rate.

16. The method according to claim 11, wherein execution of the method is based on a variable, the variable comprising at least one of a traction variable or a state variable, and wherein the variable is a maximum value, since the last opening of the disconnecting clutch, of at least one of transfer acceleration, wheel slippage rate, or yaw rate.

17. The method according to claim 11, further comprising, after the step of opening the synchronization clutch at least partially, waiting for a waiting time period before conducting one or more operations in the first operation mode or the second operation mode.

18. The method according to claim 11, wherein execution of the method is based on a waiting time period, and wherein a length of the waiting time period is derived from at least one traction variable or state variable.

19. The method according to claim 11, wherein the method further comprises waiting for a waiting time period, and further comprises prematurely terminating the waiting time period when the value of a traction variable is equal to or greater than a threshold value.

20. A multi-axle drive device, comprising: a synchronization clutch arranged in an operational connection between a first output shaft and a connecting shaft; a disconnecting clutch arranged in an operational connection between the connecting shaft and a second output shaft; wherein each of the synchronization clutch and the disconnecting clutch is configured to be opened in a first operating state and closed in a second operating state; wherein the multi-axle drive device is configured to, when switched from the second operating state to the first operating state, open the synchronization clutch at least partially, and maintain the disconnecting clutch in a closed state; wherein the multi-axle drive device is configured to, when a first operation mode is initiated, open the disconnecting clutch; and wherein the multi-axle drive device is configured to, when a second operation mode is initiated, close the synchronization clutch.

21. The multi-axle drive device according to claim 20, wherein the multi-axle drive device is configured to initiate the first operation mode when the value of at least one of a traction variable or a variable of driving dynamics is equal to or greater than a threshold value.

22. The multi-axle drive device according to claim 20, wherein the multi-axle drive device is configured to initiate the second operation mode is initiated when the value of a traction variable is less than a threshold value.

23. The multi-axle drive device according to claim 20, wherein the multi-axle drive device is configured to initiate at least one of the first operation mode or the second operation mode based on a traction variable, and wherein the traction variable comprises at least one state variable of a motor vehicle.

24. The multi-axle drive device according to claim 20, wherein the multi-axle drive device is configured to perform one or more operations based on a variable, the variable comprising at least one of a traction variable or a state variable, and wherein the variable is or is based on at least one of a transverse acceleration value, a wheel slippage value, or a yaw rate.

25. The multi-axle drive device according to claim 20, wherein the multi-axle drive device is configured to perform one or more operations based on a variable, the variable comprising at least one of a traction variable or a state variable, and wherein the variable is a maximum value, since the last opening of the disconnecting clutch, of at least one of transfer acceleration, wheel slippage rate, or yaw rate.

26. The multi-axle drive device according to claim 20, wherein the multi-axle drive device is further configured to, after opening the synchronization clutch at least partially, wait for a waiting time period before conducting one or more operations in the first operation mode or the second operation mode.

27. The multi-axle drive device according to claim 20, wherein the multi-axle drive device is configured to wait for a waiting time period, and wherein a length of the waiting time period is derived from at least one traction variable or state variable.

28. The multi-axle drive device according to claim 20, wherein the multi-axle drive device is configured to wait for a waiting time period, and wherein the multi-axle drive device is further configured to prematurely terminate the waiting time period when the value of a traction variable is equal to or greater than a threshold value.

Description

[0034] The invention will now be described in more detail based on its embodiments illustrated in the FIGURES, without limiting the invention in this manner. The single FIGURE shows:

[0035] FIGURE shows a schematic representation of a drive train of a motor vehicle, which is provided with a multi-axle drive device.

[0036] The drive train 1 is provided with a multi-axle drive device 2, which is used to selectively operate only one first axle 3, or the first axle 3 as well as a second axle 4. Each of the axles 3 and 4 is equipped in the embodiment illustrated in the FIGURE with two wheels 5, which are arranged on the partial axles 6 and 7 of the first axle 3, and on the partial axles 8 and 9 of the second axle 4. Therefore, the partial axles 6 and 7 of the first axle 3 can thus form a first output shaft 10. However, it is particularly preferred when they are connected via a differential gear, in particular an axle differential gear, to the first output shaft 10, in particular when they are operationally connected to it rigidly and/or permanently. The partial axles 8 and 9 can each be provided as a second output wave 11. Alternatively, the partial axles 8 and 9 can be connected via a differential gear, in particular an axle differential gear, to the second output wave 11.

[0037] The multi-axle drive device is provided with a connecting axle 12, by means of which an operational connection can be established between the first axle 3 and the second axle 4. The connecting shaft 12 is provided for example in the form of a Cardan shaft. A synchronization clutch 13 is arranged in an operational connection between the first output shaft 10 and the connecting shaft 12. The synchronization clutch 13 is preferably designed as a force-locking clutch. It enables in particular the transmission of any portion of the applied torque. In an operational connection between the connecting shaft 12 and the second output shaft 11 is additionally arranged a disconnecting clutch 14. In the embodiment illustrated here, two disconnecting clutches are thus provided, wherein each is arranged between a differential gear 15 and one of the both output shafts 11, or the partial axles 8 and 9.

[0038] The connecting shaft 12 is in this case operationally connected rigidly and/or permanently with the differential gear 15. The operational connection between the differential gear 15 and the connecting shaft 12 on the one hand, and the second output shaft 11 in the form of the partial axles 8 and 9 on the other hand can be selectively established or interrupted by means of disconnecting clutch 14. The disconnecting clutches are preferably in the same position, so that either an operational connection is established or interrupted between the connecting shaft 12 on the one hand, and the partial axles 8 and 9 on the other hand.

[0039] In a first operating state of the multi-drive device 2, the synchronization clutch 13 and the disconnecting clutch 14 are opened, so that the operational connection between the first output drive 10 and the second output drive 11 is interrupted. Therefore, to the extent that a disconnecting clutch 14 or a second output shat 11 are discussed hereinafter, both output shafts 11 or both disconnecting clutches 14 are meant by this within the context of the present embodiment. In a second operating state, the synchronizing clutch 13 and the disconnecting clutch 14 are fully closed. The disconnecting clutch 14 is preferably designed as a form-fitting clutch, in particular as a claw clutch.

[0040] Moreover, with an intended switching from the second operating state to the first operating state, the synchronization clutch 13 is at least partially opened and the disconnecting clutch 14 is maintained closed. It is preferred when the synchronization clutch is opened only partially so that the torque is transmitted between the first output shaft 10 and the connecting shaft 12 or the second output shaft 11. At the same time, the disconnecting clutch 14 remains closed. A traction variable is then determined and compared to a threshold value. If the traction variable exceeds or corresponds to the threshold value, the first operating state is carried out. Otherwise, the second operating a second operating mode is carried out.

[0041] In the first operating mode, the disconnecting clutch 14 is open. At the same time, it is preferred when the synchronization clutch 13 is also open, in particular fully. In the second operating mode, however, the synchronization clutch should be closed, without opening first the disconnecting clutch 14. Accordingly, in the first operating mode, the intended change from the second operating state to the to the first operating state is carried out, while it is interrupted with the second operating mode. With the method according to the invention, it is therefore possible to avoid an unnecessary switching back and forth between the operating states, while it is determined already after a partial opening of the synchronization clutch 13 whether the changeover to the first operating state will be fully carried out, or whether it will be instead interrupted.