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US 4,231,092 AGranted
Method and system for electronic simulation of a freewheel
AssigneeRobert Bosch GmbH
InventorsFerdinand Grob, Friedrich Rabus
Life of this patent
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AssigneeRobert Bosch GmbH
InventorsFerdinand Grob, Friedrich Rabus
Estimating the term…
To simulate freewheel operation, that is to allow torque transmission in one direction only, the variation with respect to time of the torque transmitted by a friction coupling clutch or brake band) is computed and the coupling is released when the transmitted torque passes through zero. When the coupling is slipping, the time at which the torque passed through zero is taken to be the time at which the input and output speed of the coupling are the same. When a slipping and a fully engaged coupling are connected in parallel, the torque transmitted by the fully engaged coupling is computed from a set of equations utilizing only parameters sensed in any case in a standard drive system. Speed sensors and a torsiometer furnish signals required for the computations. Preferably, the computations are implemented by a microprocessor.
In the drive system having an engine, driven members, and an automatic transmission having controllable friction coupling means for transmitting torque from said engine to said driven members, a method for simulating freewheel operation, comprising the steps of computing said torque transmitted by said friction coupling means and furnishing a "release" signal when the so-computed torque is equal to zero;
In a drive system having an engine, driven members and an automatic transmission having controllable friction coupling means (K.sub.X, K.sub.Y) coupled between said engine and said driven members, a method for simulating freewheel operation, comprising the steps of furnishing a "release" signal when the torque transmitted by said friction coupling means is equal to zero independently of engine speed;
In a motor vehicle having wheels (18), an engine (10), and automatic transmission means (14) interconnected between said engine and said wheels for receiving a transmission input torque (M.sub.2) from said engine and furnishing a transmission output torque (M.sub.3) to said wheels, said automatic transmission means having friction coupling means operative in response to controlled current applied thereto and having an associated gear ratio, a system for simulating freewheel operation, comprising computing means (22, 23) connected to said friction coupling means and said engine, for computing the torque transmitted by said friction coupling means and for furnishing a controlled current releasing said friction coupling when the so-computed torque is equal to zero, independently of engine speed, whereby transmission of torque from said wheels to said engine is prevented.
Dependencies are inferred from the claim text.