Driving force distribution control system for 4wd vehicle
First Claim
1. A driving force distribution control system for a vehicle, comprising:
- a torque distributing means comprising a primary drive means for transmitting a driving force from an engine of the vehicle to primary drive wheels of the vehicle, and a secondary drive means for transmitting a driving force from the engine to secondary drive wheels of the vehicle through a torque distributing clutch capable of varying the driving force transmitted to the secondary drive wheels in accordance with a control signal,said secondary drive means transmitting zero driving force to said secondary wheels when said control signal is zero increasing said drive force to said secondary wheels as said control signal increases.a means for determining a wheel speed difference which is a difference between a primary wheel speed of the primary drive wheels and a secondary wheel speed of the secondary drive wheels,a means for determining a lateral acceleration of the vehicle, anda driving force distribution controlling means for producing said control signal, said controlling means comprising a first operational means for increasing said control signal in accordance with said wheel speed difference, and a second operational means for holding said control signal equal to zero when said lateral acceleration is higher than a predetermined value, and said wheel speed difference is within a predetermined dead band range in which said primary wheel speed is lower than said secondary wheel speed and an absolute value of said wheel speed difference is smaller than a predetermined level.
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Accused Products
Abstract
A control system for a 4WD vehicle includes a drive system for directly transmitting a torque to primary drive wheels, and transmitting a torque to secondary drive wheels through a torque distributing clutch, at least one sensor for determining a front and rear wheel speed difference, at least one sensor for determining a lateral acceleration, and a control unit for controlling the engagement force of the clutch. When the primary wheel speed is lower than the secondary wheel speed, the control unit holds the clutch engagement force equal to zero to improve the steering response until the absolute value of the wheel speed difference reaches a predetermined level, and increase the clutch engagement force in accordance with the absolute value of the wheel speed difference to improve the vehicle stability after the absolute value of the wheel speed difference exceeds the predetermined level.
42 Citations
18 Claims
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1. A driving force distribution control system for a vehicle, comprising:
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a torque distributing means comprising a primary drive means for transmitting a driving force from an engine of the vehicle to primary drive wheels of the vehicle, and a secondary drive means for transmitting a driving force from the engine to secondary drive wheels of the vehicle through a torque distributing clutch capable of varying the driving force transmitted to the secondary drive wheels in accordance with a control signal, said secondary drive means transmitting zero driving force to said secondary wheels when said control signal is zero increasing said drive force to said secondary wheels as said control signal increases. a means for determining a wheel speed difference which is a difference between a primary wheel speed of the primary drive wheels and a secondary wheel speed of the secondary drive wheels, a means for determining a lateral acceleration of the vehicle, and a driving force distribution controlling means for producing said control signal, said controlling means comprising a first operational means for increasing said control signal in accordance with said wheel speed difference, and a second operational means for holding said control signal equal to zero when said lateral acceleration is higher than a predetermined value, and said wheel speed difference is within a predetermined dead band range in which said primary wheel speed is lower than said secondary wheel speed and an absolute value of said wheel speed difference is smaller than a predetermined level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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Specification