Method for reversing a direction of travel of a working machine comprising a power split transmission

Patent metadata

Field	Value
Publication number	US-10451123-B2
Application number	US-201715396891-A
Country	US
Kind code	B2
Filing date	Jan 3, 2017
Priority date	Jan 8, 2016
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

A reversing method for reversing a travel direction of a working machine with a power-split transmission in which control signals are emitted by a control unit such that a reversing clutch, for the current travel direction, is disengaged and a reversing clutch for the new travel direction is engaged. The reversing clutches are controlled by control variables. If there is a difference between a reference control magnitude and a target control variable, the control variable is adapted. An adapted control signal is emitted, with which the reversing clutches are actuated, and for determining the target control variables for the disengaging and engaging of the reversing clutches, in addition to a translational factor and a rotational factor a load-dependent factor is determined and processed.

First claim

The invention claimed is:

1. A reversing method for reversing a travel direction of a working machine with a power-split transmission, the method comprising:
emitting control signals by a control unit whereby a reversing clutch for a current travel direction is disengaged and a reversing clutch for a new travel direction is engaged;
determining and taking into account a theoretical mass of the working machine and a fraction of a moment of inertia of the transmission during a reversing process, and an actual hydraulic pressure present in the transmission for determining at least one target control variable for the disengaging and engaging of the reversing clutches; and
controlling the reversing clutches by control variables such that if there is a difference between a reference control magnitude and the at least one target control variable, emitting an adapted control signal by which the reversing clutches are actuated.

2. The method according to claim 1 , further comprising determining a load-dependent factor during braking of the working machine.

3. The method according to claim 1 , further comprising determining the load-dependent factor as a function of a thrust torque produced by the transmission and a required reversing dynamic.

4. The method according to claim 1 , further comprising using a hydrostatic power-split transmission as the transmission and determining the thrust torque produced by the transmission by a hydraulic pressure in a hydrostatic power branch of the transmission in combination with a current transmission ratio of the transmission.

5. The method according to claim 1 , further comprising determining the load-dependent factor with reference to either a torque sensor, on the transmission output, or with reference to another load-dependent signal.

6. The method according to claim 1 , further comprising if the reversing process is required, when driving downhill, the adapted control signal received for the engaging of the reversing clutch for the new travel direction has an effect that an increased torque is required at the reversing clutch being engaged.

7. The method according to claim 1 , further comprising if the reversing process is required, when driving uphill, the adapted control signal received for the engaging of the reversing clutch for the new travel direction has an effect that a reduced torque is required at the reversing clutch being engaged.

8. A reversing control device comprising:
a control unit and a storage element,
the reversing control device being designed to carry out a method of reversing a travel direction of a working machine with a power-split transmission emitting control signals by a control unit whereby a reversing clutch for a current travel direction is disengaged and a reversing clutch for a new travel direction is engaged, and the reversing clutches are controlled by control variables such that if there is a difference between a reference control magnitude and a target control variable, emitting an adapted control signal by which the reversing clutches are actuated, and determining target control variables for disengaging and engaging of the reversing clutches, and determining and taking into account a theoretical mass of the working machine, a fraction of a moment of inertia of the transmission during a reversing process, and an actual hydraulic pressure present in the transmission in such manner that, during a first step, emitted parameters are read in and compared with stored reference values, in order, during a second step, to determine the actual hydraulic pressure by which, during a third step, taking account of further parameters, the control signal for actuating the reversing clutches required for the reversing process is emitted.

9. The reversing control device according to claim 8 in combination with the working machine.

10. The use of method according to claim 1 in a working machine.

11. A reversing method for reversing a travel direction of a working machine with a power-split transmission, the method comprising:
emitting control signals from a control unit to open a first reversing clutch, which is engaged for travel in a current travel direction and to engage a second reversing clutch for travel in a new travel direction;
determining and taking into account a theoretical mass of the working machine, a fraction of a moment of inertia of the transmission during a reversing process and an actual hydraulic pressure present in the transmission for determining the target control variables for the disengaging of the first reversing clutch and the engaging of the second reversing clutch; and
controlling the first and the second reversing clutches with control variables such that if there is a difference between a reference control magnitude and a target control variable, emitting an adapted control signal with which the first and the second reversing clutches are actuated.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Geiger Simon
• Madlener Matthias

Classifications

• F16D2500/30814

  Torque of the input shaft · CPC title

• F16D2500/1112

  Heavy vehicle · CPC title

• F16D2500/3027

  Torque · CPC title

• B60W30/18036

  Reversing · CPC title

• F16D2500/3102

  Vehicle direction of travel, i.e. forward/reverse · CPC title