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U.S. Department of Energy
Office of Scientific and Technical Information

Hydraulic control system for lock-up clutch of torque converter

Patent ·
OSTI ID:5060387

A hydraulic control system is described for an automatic transmission of an automotive vehicle having an engine, comprising: a pump driven by the engine to discharge hydraulic fluid; a torque converter including a torque converter cavity, an impeller, and a turbine which are disposed in the torque converter cavity, the torque converter including a lock-up clutch which has a lock-up clutch piston movably disposed within the torque converter cavity to divide same into a lock-up release chamber and a working chamber in which the impeller and the turbine are disposed; a line pressure regulator valve connected to the pump to regulate the hydraulic fluid discharged by the pump and generate a line pressure. The line pressure regulator valve has a port and includes a means for establishing a fluid communication path between the port and the pump when the line pressure is higher than a predetermined value to allow a portion of the hydraulic fluid discharged by the oil pump to flow to the port; means communicating with the port for effecting fluid supply to the lock-up release chamber and the working chamber; and means for establishing a restricted flow communication path between the port and the pump when the line pressure is less than the predetermined value.

Assignee:
Nissan Motor Co., Ltd., Yokohama
Patent Number(s):
US 4618036
OSTI ID:
5060387
Country of Publication:
United States
Language:
English