Continuously variable transmission control system for a vehicle
AssigneeRover Group Limited
InventorsNeil David Jackson, Richard Taylor
Life of this patent
Estimating the term…
Abstract
A transmission control system for a vehicle 10 is disclosed comprising a continuously variable transmission (CVT) 14 whose transmission ratio is varied by a CVT controller 20. When the selector lever 24 is in drive D, the CVT controller 20 varies the transmission ratio in a continuous manner but, if a stepped down-shift is selected using a down-shift button DS on the steering wheel 36, a hybrid mode may be entered to allow a user to perform stepped down-shifts to provide engine braking. In the hybrid mode, stepped down-shifts can be selected but the vehicle 10 is accelerated by varying the transmission ratio in a continuous manner.
Claims45
A transmission control system for a vehicle, said control system comprising:
- a) a transmission having a variable transmission ratio;
- b) a control means for varying said transmission ratio;
- and
- c) a manually operable stepped down-shift request means for commanding desired stepped downs, said control means being arranged, during use, to vary said transmission ratio in a substantially continuous manner and also being arranged, during use, to increase said transmission ratio in steps by substantially stepped down-shifts in response to said manually operable down-shift request means,
- wherein said control means is arranged, during use, for operation in a hybrid mode in which stepped down-shifts can be made using said manually operable down-shift request means and acceleration of said vehicle is performed by operation in said continuous manner.
A method of controlling a transmission control system for a vehicle, said control system comprising:
- a transmission having a variable transmission ratio;
- a control means for varying said transmission ratio;
- and a manually operable stepped down-shift request means for commanding desired stepped downs, said control means being arranged during use to vary said transmission ratio in a substantially continuous manner and also being arranged during use to increase said transmission ratio in steps by substantially stepped down-shifts in response to said manually operable down-shift request means, the method including operating said control means in a hybrid mode which includes making stepped down-shifts using said manually operable down-shift request means and which includes accelerating said vehicle by operating said transmission ratio in said continuous manner.
Dependencies are inferred from the claim text.