Control device for oil pressure of belt type continuously variable transmission of vehicle

Abstract

Abstract PURPOSE:To reduce a power loss by controlling an oil pressure fed to one of a pair of actuators being related to an engine output condition by means of a first pressure regulating valve, and controlling an oil pressure discharged out of the other being related to a speed ratio and transmission torque by means of a second pressure regulating valve. CONSTITUTION:The pressure of a first oil passage 80 is controlled by a first pressure regulating valve 100 being related to an engine output condition by means or a throttle valve opening detecting valve 180, while controlling the pressure of a second oil passage 82 by a second pressure regulating valve 102 being related to a speed ratio and transmission torque by means of a speed ratio detecting valve 182 and a limit valve 210. And, by turning on or off a first and second solenoid valves 272, 290, a speed change directional selector valve 262 is switched over to feed working fluid in the first oil passage 80 into either of first and second actuators 70, 72 for adjusting the effective diameter of a variable pulley while discharging working fluid out of the other into the second oil passage 82, via a flow switchover valve 264. Thereby, the responsiveness of speed change and drivability can be improved while reducing the power loss of a hydraulic pump.

Inventors

• 👤 Masami Sugaya
• 👤 Katsumi Kono
• 👤 Yoshinobu Soga
• 👤 Susumu Okawa

Bibliographic Details