Position detection of a shifting device
AssigneeZF Friedrichshafen AG
InventorKai Heinrich
Life of this patent
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Abstract
A device and a method for determining the position of a gear shift element 1 in a claw clutch operated automated gear box of a vehicle. The gear shift element 1 has gear teeth that correspond to at least two gear wheels 5, 8 which have a different axial extension on both sides of a groove 9. The position of the gear shift element 1 can be determined by way of the method according to the invention.
Claims7
A device for determining a position of a gear shift element (1) of a claw clutch controlled automated gear box of a vehicle, the device having:
- at least two gear wheels (5, 8),
- a shlft fork (10),
- a mechanical shifting device (11),
- at least one sensor (14),
- a drive (12), and
- a control device (16) which is connected to the at least to one sensor (14) via a signal line (15),
- the gear shift element (1) having at least one radial groove (9) in which the shift fork (10) engages, the gear shift element (1) being axially displaced by the mechanical shifting device (11), the gear shift element (1) and the at least two gear wheels (5, 8) each have corresponding gear teeth,
- wherein the gear teeth of the gear shift element (1) have different axial widths from one another and the corresponding gear teeth of the at least two gear wheels (5, 8) have different axial widths from one another such that the gear shift element (1) must travel a greater distance to completely engage one of the two gear wheels (5, 8) then the gear shift element (1) travels to completely engage the other of the two gear wheels (5, 8), and the position of the gear shift element is determined by determining, independently of a reference point and by operation of a distance sensor (14) connected to the control device (16), a distance traveled by the gear shift element (1) to engage one of the two gear wheels (5, 8) and the distance traveled indicates the position of the gear shift element (1).
A method of determining a position of a gear shift element (1) in an automated gearbox of a vehicle having an in which a sensor (14) measures movement of a mechanical shifting device (11) by way of a drive (12) and sends a corresponding signal to at least one control device (16), the method comprising the steps of:
- controlling the drive (12), via the control device (16), in such a way that the mechanical shifting device (11) moves the gear shift element (1), via a shift fork (10), first in a direction of a first gear wheel (5) until further movement is prevented and a measured current of the drive (12) reaches a limit value,
- a counter (24) of sensor signals in the control device (16) to a value zero,
- controlling the drive (12) in such a way that the mechanical shifting element (11) moves gear shift element (1) in a direction of a second gear wheel (8) until movement is prevented and the measured current of the drive (12) reaches again a limit value,
- comparing a sum of the measured sensor signals measured in the control device (16) to fixed values at a transmitter wheel (13), and
- determining the position of the gear shift element (1) upon conformity of a sum with one of the fixed values.
Dependencies are inferred from the claim text.