Control for automatic transmissions
First Claim
1. A control system for vehicle automatic transmissions comprising hydraulic actuator means for engaging friction engaging means for establishing a driving gear train, hydraulic conduit means for supplying hydraulic pressure to said hydraulic actuator means, control valve means provided in said hydraulic conduit means to connect the actuator means alternately to hydraulic source means and drain conduit means, pressure reducing valve means provided in said drain conduit means for producing a pressure which is lower than a pressure for making the friction engaging means engage, vehicle speed detecting means for detecting vehicle speed and producing a low vehicle speed signal showing that the vehicle speed is below a predetermined value, position detecting means for detecting position of an engine power control member and producing a position signal when the control member is in a low engine output position smaller than a predetermined position, brake actuation means for producing a brake signal when vehicle brake means is in operation, range detecting means for detecting position of a manually operated shift lever and producing a running range signal when said shift lever is in a running range, valve actuating means for actuating said control valve means, control means for controlling operation of said valve actuating means, said control means being responsive to said low vehicle speed signal, said position signal, said brake signal, and said running range signal for producing a control signal to operate said valve actuating means for moving said control valve means so that the hydraulic actuator means is connected to the drain conduit means when all of said signals are received, said control means including time delay means for applying a time delay to said running range signal so that the control signal is produced after a predetermined delay time when the manual shift lever is moved to a running range.
1 Assignment
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Accused Products
Abstract
A vehicle having an automatic transmission including a hydraulic torque converter and a gear mechanism driven by the torque converter. The gear mechanism includes a hydraulically operated clutch for establishing a forward driving gear train. A control circuit is provided for disengaging the clutch when the engine speed is idling and the vehicle brake is actuated with the select valve of the transmission is in a running range and the engine throttle valve in a closed position so that the forward driving gear train is disconnected.
18 Citations
18 Claims
- 1. A control system for vehicle automatic transmissions comprising hydraulic actuator means for engaging friction engaging means for establishing a driving gear train, hydraulic conduit means for supplying hydraulic pressure to said hydraulic actuator means, control valve means provided in said hydraulic conduit means to connect the actuator means alternately to hydraulic source means and drain conduit means, pressure reducing valve means provided in said drain conduit means for producing a pressure which is lower than a pressure for making the friction engaging means engage, vehicle speed detecting means for detecting vehicle speed and producing a low vehicle speed signal showing that the vehicle speed is below a predetermined value, position detecting means for detecting position of an engine power control member and producing a position signal when the control member is in a low engine output position smaller than a predetermined position, brake actuation means for producing a brake signal when vehicle brake means is in operation, range detecting means for detecting position of a manually operated shift lever and producing a running range signal when said shift lever is in a running range, valve actuating means for actuating said control valve means, control means for controlling operation of said valve actuating means, said control means being responsive to said low vehicle speed signal, said position signal, said brake signal, and said running range signal for producing a control signal to operate said valve actuating means for moving said control valve means so that the hydraulic actuator means is connected to the drain conduit means when all of said signals are received, said control means including time delay means for applying a time delay to said running range signal so that the control signal is produced after a predetermined delay time when the manual shift lever is moved to a running range.
- 10. A control system for vehicle automatic transmissions comprising first hydraulic actuator means for engaging forward driving friction engaging means for establishing a forward driving gear train, second hydraulic actuator means for engaging reverse driving friction engaging means for establishing a reverse driving gear train, first hydraulic conduit means for supplying hydraulic pressure to said first hydraulic actuator means, second hydraulic conduit means for supplying hydraulic pressure to said second hydraulic actuator means, control valve means provided in at least one of said hydraulic conduit means to connect the actuator means associated with said hydraulic conduit means alternately to hydraulic source means and drain conduit means, pressure reducing valve means provided in said drain conduit means for producing a pressure which is lower than a pressure for making the friction engaging means engage, vehicle speed detecting means for detecting vehicle speed and producing a low vehicle speed signal showing that the vehicle speed is below a predetermined value, position detecting means for detecting position of an engine power control member and producing a position signal when the control member is in a low engine output position smaller than a predetermined position, brake actuation detecting means for producing a brake signal when vehicle brake means is in operation, engine speed detecting means for detecting an engine operating condition and producing a low engine speed signal showing that the engine speed is lower than a predetermind value, range detecting means for detecting position of a manually operated shift lever and producing a running range signal when said shift lever is in a running range, valve actuating means for actuating said control valve means, control means for controlling operation of said valve actuating means, said control means being responsive to said low vehicle speed signal, said position signal, said brake signal, said low engine speed signal and said running range signal for producing a control signal to operate said valve actuating means for moving said control valve means so that the hydraulic actuator means is connected to the drain conduit means when all of said signals are received, said control means including time delay means for applying a time delay to said running range signal so that the control signal is produced after a predetermined delay time when the manual shift lever is moved to a running range.
- 11. A control system for vehicle automatic transmissions comprising first hydraulic actuator means for engaging forward driving clutch means for establishing a forward driving gear train, second hydraulic actuator means for engaging reverse driving clutch means for establishing a reverse driving gear train, first hydraulic conduit means for supplying hydraulic pressure to said first hydraulic actuator means, second hydraulic conduit means for supplying hydraulic pressure to said second hydraulic actuator means, control valve means provided in at least one of said hydraulic conduit means to connect the actuator means associated with said hydraulic conduit means alternately to hydraulic source means and drain conduit means, pressure reducing valve means provided in said drain conduit means for producing a pressure which is lower than a pressure for making the clutch means engage, vehicle speed detecting means for detecting vehicle speed and producing a low vehicle speed signal showing that the vehicle speed is below a predetermined value, position detecting means for detecting position of an engine power control member and producing a position signal when the control member is in a low engine output position smaller than a predetermined position, brake actuation detecting means for producing a brake signal when vehicle brake means is in operation, engine speed detecting means for detecting an engine operating condition and producing a low engine speed signal showing that the engine speed is lower than a predetermined value, range detecting means for detecting position of a manually operated shift lever and producing a running range signal when said shift lever is in a running range, valve actuating means for actuating said control valve means, control means for controlling operation of said valve actuating means, said control means being responsive to said low vehicle speed signal, said position signal, said brake signal, said low engine speed signal and said running range signal for producing a control signal to operate said valve actuating means for moving said control valve means so that the hydraulic actuator means is connected to the drain conduit means when all of said signals are received, said control means including time delay means for applying a time delay to said running range signal so that the control signal is produced after a predetermined time delay when the manual shfit lever is moved to a running range.
Specification