System for controlling the pressure of oil in a system for a continuously variable transmission

Patent · Tue Sep 20 00:00:00 EDT 1988

OSTI ID:6556602

Miyawaki, M

This patent describes a control system for a continuously variable transmission for transmitting the power of an internal combustion engine having a throttle valve to driving wheels of a motor vehicle through a clutch, the transmission 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 of the driven pulley, and a belt engaged with both pulleys, the control system having a line pressure control valve having ports and a shiftable spool, a transmission ratio control having ports and a shiftable spool, and a first hydraulic circuit having a pump for supplying oil regulated by the line pressure control valve to the first hydraulic cylinder via the transmission ratio control valve and to the second hydraulic cylinder. The improvement in the system consists of: a second hydraulic circuit for supplying control oil to the line pressure control so as to shift the spool of the line pressure control valve; control valve means provided in the second hydraulic circuit for controlling the amount of the control oil supplied to the line pressure control valve; sensor means for sensing operating conditions and for producing first signals; first means responsive to at least one of the first signals for producing an engine torque representing engine torque in acceleration state and state state respectively; second means responsive to at least one of the first signals when the throttle valve is closed during driving of the vehicle for producing an acceleration/deceleration signal representing engine braking conditions.

• Assignee: Fuji Jukogyo Kabushiki Kaisha, Tokyo
• Patent Number(s): US 4771658
• OSTI ID: 6556602
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330602* -- Vehicle Design Factors-- Engine-Transmission Matching
CONTROL
CONTROL EQUIPMENT
ENGINES
EQUIPMENT
FLOW REGULATORS
FLUID MECHANICS
HEAT ENGINES
HYDRAULICS
INTERNAL COMBUSTION ENGINES
LUBRICANTS
LUBRICATING OILS
LUBRICATION
MACHINE PARTS
MECHANICAL TRANSMISSIONS
MECHANICS
OILS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PETROLEUM PRODUCTS
PRESSURE CONTROL
VALVES
VEHICLES
WHEELS