Engine brake control in automatic transmission
This patent describes an engine braking control for a transmission for an automotive vehicle having an engine, the transmission including an input member drivingly coupled to the engine and an output member subject to load from driving wheels of the automotive vehicle, the transmission also including a first rotary member, a second rotary member, a hydraulically operated clutch selectively establishing a drive connection between the first rotary member and the second rotary member, and a one-way clutch arranged in parallel to the hydraulically operated clutch such that when the hydraulically operated clutch is released, the one-way clutch transmits forward torque from the first rotary member to the second rotary member, but interrupts transmission of revers torque to the first rotary member from the second rotary member, the engine braking control comprising: means for providing an engine braking command fluid pressure signal when demanded by a vehicle operator; a valve means for normally discharging hydraulic fluid from the hydraulically operated clutch to deactivate the hydraulically operated clutch, the valve means being fluidly connected to the hydraulically operated clutch, the engine braking command fluid pressure signal providing means and a drain port. The valve means including a valve spool having a first position where the hydraulically operated clutch is allowed to communicate with the drain port to permit discharge of hydraulic fluid therefrom and thus the hydraulically operated clutch is caused to be deactivated and a second position where the hydraulically operated clutch is disconnected from the drain port and allowed to communicate with the engine braking command fluid pressure signal.
- Assignee:
- Nissan Motor Co., Ltd., Yokohama
- Patent Number(s):
- US 4770066
- OSTI ID:
- 6620546
- Resource Relation:
- Patent File Date: Filed date 14 Jul 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BRAKES
CONTROL SYSTEMS
INTERNAL COMBUSTION ENGINES
MECHANICAL TRANSMISSIONS
AUTOMOBILES
CONTROL EQUIPMENT
GEARS
HYDRAULICS
PRESSURE MEASUREMENT
VALVES
ENGINES
EQUIPMENT
FLOW REGULATORS
FLUID MECHANICS
HEAT ENGINES
MACHINE PARTS
MECHANICS
VEHICLES
330100* - Internal Combustion Engines