Vehicle Transmission Comprising A Parking Brake And Method For Controlling The Same
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Accused Products
Abstract
A vehicle transmission having shifting elements (A-E) and a parking brake for locking a drive train output and a method for controlling the transmission. Activation of the parking brake depends on a driver'"'"'s control action. Deactivating the parking brake, when the vehicle is on a slope greater or lesser than a preset value and depending on the slope, a combination of shifting elements (A, D) or (B, D) frictionally slip, such that the output rotates against the strain on a parking brake locking element, caused by the slope, to partially eliminate this strain. Next, one of shifting elements (C, A or B) engages locking the output. The parking brake is then released and finally, the engaged shifting element (C or A or B) is disengaged in a regulated manner, such that the output can be driven according to the driver'"'"'s control action.
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Citations
67 Claims
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1-37. -37. (canceled)
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38. A method of controlling a transmission (4) of a vehicle having multiple frictionally engageable shifting elements (A, B, C, D, E) and a parking brake (8), which has a positive locking element for engaging an output (5) of a drive train (1), the method being initiated upon a driver'"'"'s control action for disengagement of the parking brake (8) from the output (5) and when a roadway gradient (grad) is one of greater than a preset first positive threshold value or smaller than a preset first negative threshold value, the method comprising the steps of:
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slidably engaging one of a combination of a first shifting element (A) and a fourth shifting element (D) and a combination of a second shifting element (B) and a fourth shifting element (D) depending on the roadway gradient (grad) such that the output (5) rotates in a direction opposite to a strain force acting between the engaged positive locking element of the parking brake (8) and the output (5) until the strain force is at least partially eliminated;
engaging at least one of a third shifting element (C), the first shifting element (A) and the second shifting element (B) to lock the output (5);
disengaging the positive locking element of the parking brake (8) from the output (5); and
controllably disengaging at least one the third shifting element (C), the first shifting element (A) and the second shifting element (B) from the output (5) such that the output (5) is rotatable in a direction corresponding to the driver'"'"'s control action. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62)
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63. A vehicle transmission (4) having first, second, third, fourth, and fifth shifting elements (A, B, C, D, E) whose selective engagement implements a variety of gear ratios, a parking brake (8) with a positive locking element which locks an output (5) of a drive train (1), a control device for controllably engaging at least one of the first, the second, the third, the fourth, and the fifth shifting elements (A, B, C, D, E), depending on a driver'"'"'s control action, to lock the output (5) when the parking brake (8) is activated, and controllably deactivating the parking brake (8) when motion of the vehicle is desired,
wherein when the driver'"'"'s control action indicates a deactivation of the parking brake (8) and a roadway gradient (grad) is one of greater than a preset first positive threshold value and smaller than a preset first negative threshold value, one of a combination of the first and the fourth shifting elements (A, D) and the second and the fourth shifting elements (B, D) are slidably engaged, depending on the roadway gradient (grad), such that the output (5) rotates opposite a direction of a rotational strain on the activated parking brake (8) until the rotational strain on the parking brake (8) is at least partially eliminated, at least one of the first, the second, and the third shifting elements (A, B, C) is additionally engaged to locking the output (5), the positive locking element of the parking brake (8) is released, and at least one of the first, the second and the third shifting elements (A, B, C), engaged for locking the output (5), is controllably disengaged to enable the output (5) to rotate according to the driver'"'"'s control action.
Specification