Method and control apparatus for operating a positive shift element of a transmission of a vehicle, transmission and vehicle

Patent metadata

Field	Value
Publication number	US-12264739-B2
Application number	US-202318512674-A
Country	US
Kind code	B2
Filing date	Nov 17, 2023
Priority date	Nov 18, 2022
Publication date	Apr 1, 2025
Grant date	Apr 1, 2025

Abstract

Disclosed is a method for operating an interlocking shifting element of a transmission of a vehicle, the interlocking shifting element having shifting element halves which can be moved relative to one another when opening and closing the interlocking shifting element. An electric actuator is arranged to about the relative movement between the shifting element halves when the interlocking shifting element is opened and/or closed. After recognizing a tooth-on-tooth position in the interlocking shifting element, a target torque to be applied at the transmission input is determined as a function of an electric current strength through the electric actuator of the interlocking shifting element, where the target torque is sufficient to resolve the tooth-on-tooth position in the interlocking shifting element.

First claim

The invention claimed is:

1. A method for operating an interlocking shifting element of a transmission of a vehicle, wherein the interlocking shifting element comprises shifting element halves configured to be moved relative to one another when opening and closing the interlocking shifting element, and wherein an electric actuator is configured and arranged to bring about the relative movement between the shifting element halves when opening or closing the interlocking shifting element, the method comprising:
recognizing a tooth-on-tooth position in the interlocking shifting element; and
determining, as a function of an electric current strength through the electric actuator, a target torque to be applied at a transmission input of the transmission sufficient to resolve the tooth-on-tooth position in the interlocking shifting element;
wherein determining the target torque is performed according to the following equation:

M
SOLL

=

K
M

*

I
A

r
S

*

μ
Z

*

r
Z

+

M
0

and wherein
M SOLL is the target torque,
I A is the electric current strength of the electric actuator,
K M is a proportionality constant,
r S is a radius of a spindle of the electric actuator,
μ Z is a coefficient of friction valid for the transmission,
r Z is a friction radius of the transmission valid for the interlocking shifting element,
M 0 is a torque to be transmitted by the interlocking shifting element.

2. The method according to claim 1 , wherein the vehicle comprises a drive unit, the method further comprising:
controlling the drive unit to deliver the target torque at the transmission input to resolve the tooth-on-tooth position in the interlocking shifting element.

3. The method according to claim 2 , wherein the drive unit comprises an electric machine.

4. The method according to claim 1 , wherein recognizing the tooth-on-tooth position is performed as a function of the electric current strength through the electric actuator.

5. The method according to claim 4 , wherein recognizing the tooth-on-tooth position comprises:
activating, by the electric actuator, the interlocking shifting element;
recognizing, before a lapse of a pre-defined time interval since a beginning of activating the interlocking shifting element by the electric actuator, that the electric current strength in the electric actuator is greater than a limit value; and
determining a shifting position of the interlocking shifting element to be the tooth-on-tooth position of the interlocking shifting element based at least in part on the electric current strength being greater than the limit value.

6. A control unit of a vehicle transmission, wherein the control unit is configured to
(i) bring about opening and/or closing of an interlocking shifting element by activating an electric actuator to produce a relative movement between shifting element halves of the interlocking shifting element;
(ii) recognize a tooth-on-tooth position in the interlocking shifting element; and
(iii) determine, as a function of an electric current strength in the electric actuator, a target torque to be provided at a transmission input of the transmission sufficient to resolve the tooth-on-tooth position in the interlocking shifting element;
wherein the control unit is configured to automatically carry out the method of claim 1 .

7. A transmission of a vehicle, comprising the control unit of claim 6 .

8. A vehicle comprising the control unit of claim 6 .

9. The vehicle of claim 8 , wherein the vehicle is an electric vehicle.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Moser Wilhelm
• Chamaken Kamde Alain Tierry

Classifications

• F16H63/502

  for smoothing gear shifts · CPC title

• F16H2059/6807

  Status of gear-change operation, e.g. clutch fully engaged · CPC title

• F16H63/04

  a single final output mechanism being moved by a single final actuating mechanism · CPC title

• F16H63/304

  the final output mechanisms comprising elements moved by electrical or magnetic force (band brake actuating mechanisms F16H63/3003) · CPC title

• F16H2061/047

  by preventing or solving a tooth butt situation upon engagement failure due to misalignment of teeth · CPC title