US 6,550,559 B1 · System and method for controlling hub locks in a four-wheel drive vehicle

Abstract

A control system or apparatus (10) is provided which is deployed within a four-wheel drive vehicle (12) and which is adapted to automatically control the activation and deactivation (i.e., locking and unlocking) of hub locks (44) according to a certain control strategy. Hub locks (44) are effective to operatively connect and disconnect the front wheels (14) of vehicle (12) to the front axle assembly (16), thereby allowing torque from the front driveshaft (22) of the vehicle to be transferred to the front wheels (14) when the vehicle (12) operates in a four-wheel drive mode. Control system (10) is effective to detect system faults and malfunctions and to selectively alter the hub locks control strategy in response to such a detection, thereby substantially preventing the undesired locking/unlocking of the hub locks (44) resulting in possible ratcheting, binding or damage to the hub locks (44).

Claims13

Dependent claims

A method for controlling a hub locks assembly in a four-wheel drive vehicle having a transfer case which includes a motor which is movable in a plurality of positions, effective to selectively cause said transfer case to operate in a plurality of operating modes, and an encoder which provides position readings corresponding to said position of said motor, said method comprising the steps of:

providing a controller which is coupled to said encoder and said hub locks assembly, wherein said controller receives said position readings corresponding to said position of said transfer case motor from said encoder;
selectively locking and unlocking said hub locks based upon said position readings;
receiving a position reading from said encoder indicating a changed position of said motor;
determining whether said motor is turned off;
and
ignoring said position reading from said encoder indicating a changed position of said motor when said motor is turned off.

3 more elements

A method for controlling hub locks in a four wheel drive vehicle including a transfer case having a motor which may be positioned in a plurality of motor positions, said method comprising the steps of:

defining each of said plurality of motor positions into distinct physical positions, wherein said distinct physical positions comprise a two wheel drive high position, a four wheel drive high position, a neutral position, a four wheel low position, first between gears positions are disposed between said two wheel drive high position and said four wheel drive high position, second between gears positions which are disposed between said four wheel drive high position and said neutral position, third between gears positions which are disposed between said neutral position and said four wheel drive low position;
providing an encoder which is coupled to said motor and which generates signals corresponding to each of said distinct motor positions;
unlocking said hub locks if said encoder signal corresponds to a two wheel drive high position;
locking said hub locks if said encoder signal corresponds to said four wheel drive high position, said four wheel drive low position, said second between gears positions, and said third between gears positions;
and
ignoring said encoder signals corresponding to said first between gears positions.

3 more elements

Dependencies are inferred from the claim text.

System and method for controlling hub locks in a four-wheel drive vehicle

Life of this patent

System and method for controlling hub locks in a four-wheel drive vehicle

Life of this patent

Abstract

Claims13