System for controlling line pressure of a continuously variable transmission for a motor vehicle

Patent · Tue Feb 16 04:00:00 EST 1988

OSTI ID:5054492

Tezuka, K

This patent describes a control system for a continuously variable transmission for transmitting the power of an internal combustion engine to driving wheels of a motor vehicle, having a drive pulley including a hydraulically shiftable disc and a first hydraulic cylinder for shifting the disc, a driven pulley including a hydraulically shiftable disc and a second hydraulic cylinder for operating the disc, a belt engaged with both pulleys, a transmission ratio control valve having ports and a spool, a line pressure control valve having ports and a spool, a first hydraulic circuit having a pump for supplying oil to the first and second cylinders through the line pressure control valve and the transmission ratio control valve. The system comprises: a clutch for transmitting torque of the engine to the transmission; first means for shifting the spool of the line pressure control valve in dependence on operating conditions of the engine so as to provide a line pressure; an engine speed sensor for producing an engine speed signal dependent on speed of the engine; second means responsive to the engine speed signal for producing an engine torque signal dependent on output torque of the engine; third means for producing a clutch torque signal dependent on the transmitting of the torque of the clutch; detecting means for detecting engaging conditions of the clutch and for producing a clutch slipping signal when the clutch slips and producing a clutch engaging signal when the clutch is engaged; selector means responsive to the clutch slipping signal for applying the clutch torque signal to the first means and responsive to the clutch engaging signal for applying the engine torque signal to the first means, whereby the line pressure is controlled in accordance with the engaging conditions of the clutch.

• Assignee: Fuji Jukogyo Kabushiki Kaisha, Tokyo
• Patent Number(s): US 4724724
• OSTI ID: 5054492
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330602* -- Vehicle Design Factors-- Engine-Transmission Matching
CONTROL
CONTROL EQUIPMENT
CONTROL SYSTEMS
DESIGN
ELECTRONIC CIRCUITS
EQUIPMENT
FLOW REGULATORS
GEARS
MACHINE PARTS
MECHANICAL TRANSMISSIONS
OPERATION
PRESSURE CONTROL
PULSE CIRCUITS
PUMPS
SIGNAL CONDITIONERS
TORQUE
VALVES
VELOCITY