Motor vehicle having an automatically shifted transmission

• US 5,919,112 A
• Filed: 06/23/1997
• Issued: 07/06/1999
• Est. Priority Date: 06/22/1996
• Status: Expired due to Term

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Ehrmaier, Rudolf, Neuner, Josef, Michael, Joerg
• Primary Examiner(s): Wright, Dirk
• Application Number:
  US08/880,681
• Time in Patent Office: 743 Days
• Field of Search: 477/97, 477/99
• US Class Current: 477/99
• CPC Class Codes: B60W 2540/06 Ignition switch
• CPC Class Codes: F16H 2059/746 Engine running state, e.g. on-off of ignition switch
• CPC Class Codes: F16H 59/0204 for automatic transmissions with means for range selection and manual shifting, e.g. range selector with tiptronic
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 59/50 Inputs being a function of the status of the machine, e.g. position of doors or safety belts
• CPC Class Codes: F16H 63/483 Circuits for controlling engagement of parking locks or brakes

Abstract

A motor vehicle is described which has an engine and an automatically shifted transmission. As an operating element, the transmission has at least one selecting device by which a driver controls an electric transmission control device. As a function of a driving position selected on the selecting device and of other operating parameters of the motor vehicle, the electric transmission control device controls a parking position function of the automatic transmission among other functions. In this case, the parking position will be engaged in the automatically shifted transmission when the driving speed of the motor vehicle is equal to zero and simultaneously the ignition circuit was interrupted by the ignition key and after a predetermined time period has elapsed or when a vehicle door is opened. Alternatively, the parking position is engaged or no later than when the ignition key is removed from the ignition lock.

Claims

1. A motor vehicle having an engine and an automatically shifted transmission, said automatically shifted transmission having at least one selecting device as an operating element thereof, comprising:

an electric transmission control device operable via a driver using said at least one selecting device, said electric transmission control device controlling a parking position function of the automatically shifted transmission as a function of a driving position selected by said at least one selecting device and other operating parameters of the motor vehicle;

wherein said parking position is engaged in the automatically shifted transmission when a driving speed of the motor vehicle is zero and, simultaneously, an ignition circuit is interrupted, and after one of an elapsing of a predetermined time period and an opening of a vehicle door; and

wherein said parking position is engaged in all cases no later than when an ignition key is removed from an ignition lock.

2. The motor vehicle according to claim 1, wherein the engagement of the parking position is prevented when a driving position N is selected via the selecting device immediately before a switching-off of the engine, or within a predetermined time period after the switching-off of the engine.

3. The motor vehicle according to claim 1, wherein a release of the parking position occurs hydraulically and a spring is prestressed during said release.

4. The motor vehicle according to claim 2, wherein a release of the parking position occurs hydraulically and a spring is prestressed during said release.

5. The motor vehicle according to claim 3, further comprising a solenoid as an impedance element by which said engagement of the parking position is preventable.

6. The motor vehicle according to claim 5, wherein said impedance element cancels an impeding effect only when a position P is engaged.

7. The motor vehicle according to claim 5, wherein said impedance element does not exercise an impeding effect during said release of the parking position.

8. The motor vehicle according to claim 6, wherein said impedance element does not exercise an impeding effect during said release of the parking position.

9. The motor vehicle according to claim 1, wherein said at least one selecting device is a selector lever movable in at least two operating planes situated approximately perpendicularly with respect to one another, said selector lever automatically returning to a starting position in a central location.

10. The motor vehicle according to claim 1, further comprising a display device which displays to the driver a driving position adjustably selected via the selecting device, said selecting device being a selector lever.

11. The motor vehicle according to claim 10, wherein said display device additionally displays shifting possibilities for the selector lever.

12. The motor vehicle according to claim 10, wherein said display device comprises a further display plane such that more than four different functions are assignable to four moving directions of the selector lever, said more than four different functions being displayable via the display device.

13. The motor vehicle according to claim 11, wherein said display device comprises a further display plane such that more than four different functions are assignable to four moving directions of the selector lever, said more than four different functions being displayable via the display device.

14. The motor vehicle according to claim 1, further comprising a display device having a display controlled in all driving positions via said electric transmission control device;

and

a sensor arranged in the transmission to determine an engaged driving position P, said sensor controlling the display device.

15. The motor vehicle according to claim 14, wherein when the ignition is switched off, said electric transmission control device is switched off when the display device is controlled via the sensor in the transmission.

16. The motor vehicle according to claim 15, wherein the display of the display device is switched off when the ignition is switched off and the driving position P is engaged after a predetermined time period, or when an ignition key is removed from an ignition lock with a switching-off of load devices, or when a door lock of the motor vehicle is operated.

17. The motor vehicle according to claim 1, further comprising an additional operating element by which the driver engages the parking position.

18. The motor vehicle according to claim 17, wherein the engaging of the parking position via the additional operating element operates a parking brake.

19. The motor vehicle according to claim 1, wherein an ignition lock is provided with an electromagnetic impedance element which permits withdrawal of said ignition key only when the driving speed is equal to zero or when the driving speed is equal to zero and the service brake is simultaneously operated.

20. The motor vehicle according to claim 19, wherein said electromagnetic impedance element is controlled via at least one of a transmission control device and a brake control device.

21. The motor vehicle according to claim 1, wherein via said electric transmission control device, a driving position for a driving operation of the motor vehicle is engaged only if a service brake is simultaneously operated.

22. The motor vehicle according to claim 21, wherein at least one of an acoustic and visual signal device is operated when an attempt to engage a driving position is made for a driving operation without operating the service brake.

23. The motor vehicle according to claim 1, wherein said parking position is made inoperative via a mechanical emergency release system.

24. The motor vehicle according to claim 23, wherein said mechanical emergency release system is operable from a passenger compartment of the motor vehicle.

25. A method of operating an automatic transmission in a motor vehicle having an engine, said automatic transmission having a selecting device as an operating element by which a driver controls an electric transmission control unit, which electric transmission control unit controls a parking position of the automatic transmission as a function of a driving position selected via the selecting device, the method comprising the steps of:

automatically engaging the parking position function in the automatic transmission upon the following conditions;

determining a driving speed of the motor vehicle to be zero and, simultaneously, an ignition circuit to be interrupted; and

when one of a predetermined time period has elapsed and a vehicle door is opened;

automatically engaging the parking position in the automatic transmission in any event no later than when an ignition key is determined to be removed from an ignition lock.