ENGINE TORQUE TRUNCATION METHOD FOR A FOUR-WHEEL DRIVE VEHICLE
First Claim
1. A method for regulating driving torque transfer through a friction clutch in a torque transfer case for a powertrain for a four-wheel drive vehicle;
- the powertrain including an engine, a geared transmission between the engine and the torque transfer case;
an engine controller and a powertrain controller;
a primary axle driveshaft connected driveably to torque output elements of the torque transfer case and a secondary axle driveshaft connected to torque output elements of the torque transfer case through the friction clutch;
the method comprising;
engaging the friction clutch to effect power transfer from the engine to the secondary axle driveshaft as engine power is delivered to the primary axle driveshaft;
determining whether driving friction elements of the friction clutch are slipping; and
reducing engine torque until slipping of the diving friction elements of the friction clutch is eliminated.
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Accused Products
Abstract
A four wheel drive powertrain control for an automotive vehicle is disclosed. It includes a torque transfer case that distributes power from an engine-powered transfer case mainshaft to a secondary driving axle through a friction clutch as power is distributed directly from the engine-powered mainshaft to a primary driving axle. The friction clutch capacity is sufficient to mechanically lock the transfer case in a four wheel drive mode. If the clutch torque capacity is exceeded, a control algorithm will strategically ramp down engine torque requests by a powertrain controller to eliminate clutch slip.
40 Citations
9 Claims
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1. A method for regulating driving torque transfer through a friction clutch in a torque transfer case for a powertrain for a four-wheel drive vehicle;
- the powertrain including an engine, a geared transmission between the engine and the torque transfer case;
an engine controller and a powertrain controller;
a primary axle driveshaft connected driveably to torque output elements of the torque transfer case and a secondary axle driveshaft connected to torque output elements of the torque transfer case through the friction clutch;
the method comprising;
engaging the friction clutch to effect power transfer from the engine to the secondary axle driveshaft as engine power is delivered to the primary axle driveshaft;
determining whether driving friction elements of the friction clutch are slipping; and
reducing engine torque until slipping of the diving friction elements of the friction clutch is eliminated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- the powertrain including an engine, a geared transmission between the engine and the torque transfer case;
Specification