Method for controlling a gear brake for an automated change-speed gearbox

摘要

A method of controlling a transmission brake of an automated change-speed transmission having a control cylinder, that is pressurized by inlet and outlet valves, and an upstream main cut-off valve by which a nominal pressure, supplied to the control cylinder, is regulated. Functional deviations of the transmission brake can be considered during a shifting operation, when the transmission is in neutral, the motor coupling clutch is disengaged and the transmission brake is engaged. The rotational speed gradient and the mass of the transmission components to be braked are determined and used to calculate the current braking torque of the transmission brake. The current braking torque relates to the current regulated nominal pressure, and the determined values are stored in a control unit and used during subsequent actuation of the transmission brake.

主权项

1. A method of controlling operation of a transmission brake in an automated change-speed transmission that is couplable by a separator clutch to a drive engine of a motor vehicle, the transmission brake is controlled by a control cylinder (8) that is pressure-medium-actuated by way of associated inlet and outlet valves (16, 18), and at least one main cut-off valve (4) is arranged upstream from the inlet and the outlet valves (16, 18) by which a nominal pressure, of a pressure medium supplied to the control cylinder (8), is controllable, the method comprising the steps of:
determining, with a control unit, a rotational speed gradient of rotating transmission components to be braked by the transmission brake, when in a shifting operation with the transmission in neutral, the separator clutch disengaged and the transmission brake engaged; determining, with the control unit, a mass of the rotating transmission components to be braked by the transmission brake during the shifting operation; calculating, with the control unit, a value of currently effective braking torque of the transmission brake from the determined speed gradient and the determined mass to be braked; associating, with the control unit, the determined value of the current braking torque with a current regulated value of a nominal pressure; storing the value of the nominal pressure and the value of the braking torque in a data memory of the control unit; and using the stored values of the nominal pressure and the braking torque, for either controlling or regulating braking action, during subsequent actuations of the transmission brake.