Method of operating the power train of a vehicle
First Claim
1. A method for operating a drive-train of a motor vehicle having a drive engine, a motor vehicle transmission and at least one drive axle, the method comprising:
- automatically separating a connection between the drive engine and the at least one drive axle of the motor vehicle by a function,actuating a service brake of the motor vehicle to activate the function,during a course of the function, triggered by a braking process, determining a brake pressure applied for the braking process, andautomatically determining a starting gear as a function of the brake pressure.
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Accused Products
Abstract
A method of operating a drive-train (1) of a motor vehicle, in particular an agricultural or municipal utility vehicle, having a drive engine (2), a motor vehicle transmission (4) and at least one drive axle (6). A connection between the drive engine (2) and the at least one drive axle (6) of the motor vehicle is separate automatically by way of a function, and a service brake (11) of the motor vehicle has to be actuated for activation of the function. To ensure an appropriate starting gear selection in various operating situations, during the course of the function triggered by a braking process, a brake pressure (pBrems), applied during the process, is determined and a starting gear is automatically determined as a function of the brake pressure (pBrems).
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Citations
13 Claims
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1. A method for operating a drive-train of a motor vehicle having a drive engine, a motor vehicle transmission and at least one drive axle, the method comprising:
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automatically separating a connection between the drive engine and the at least one drive axle of the motor vehicle by a function, actuating a service brake of the motor vehicle to activate the function, during a course of the function, triggered by a braking process, determining a brake pressure applied for the braking process, and automatically determining a starting gear as a function of the brake pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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- 9. A control unit for a motor vehicle transmission arranged in a drive-train of a motor vehicle, which is connected to a first device for regulating a function for separating a connection between a drive engine and at least one drive axle of the motor vehicle, and a second device for automatic selection of a starting gear of the motor vehicle transmission, the function activated by the first device brings about a separation of the connection between the drive engine and the at least one drive axle of the motor vehicle, for the activation of the function a service brake of the motor vehicle has to be actuated, and, when the function that is triggered by a braking process is carried out, a brake pressure applied for the process is determinable and, as a function of the brake pressure, a starting gear is automatically determined, and for an automatic selection of the starting gear, a brake pressure of at least one brake circuit of the service brake must exceed a first brake pressure limit value in order for the starting gear to be determined as a function of the brake pressure.
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13. A method of operating a drive-train of a motor vehicle having a drive engine, a motor vehicle transmission, at least one drive axle, the method comprising:
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initiating the method by actuating a service brake of the motor vehicle, when a drive connection between the drive engine and the at least one drive axle of the motor vehicle is disengaged, determining, via a pressure sensor, a braking pressure applied for actuating the service brake; automatically determining, via a transmission control unit, a starting gear of the transmission based on the determined braking pressure; selecting, via the transmission control unit, a pre-set starting gear if the determined braking pressure is less than or equal to a first pressure limit; selecting, via the transmission control unit, another starting gear if the determined braking pressure is greater than the first pressure limit and lower than or equal to a second brake pressure limit value; selecting, via the transmission control unit, a further starting gear if the determined braking pressure is greater than the second pressure limit; and engaging, via the transmission control device, the selected one of the pre-set starting gear, the another starting gear, and the further starting gear for starting the motor vehicle.
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Specification