Variable force solenoid pressure control for an automatic transmission

Patent · Tue May 30 04:00:00 EDT 1989

OSTI ID:5526405

Lemieux, G E

This patent describes a hydraulic pressure control circuit for an automatic transmission having fluid pressure operated clutch and brake servo. The controlling transmission consists of: a pump and a main pressure regulator valve means for establishing a regulated pressure in the control circuit; a variable force solenoid valve means for developing a pressure proportional to engine torque including a variable force solenoid connected to pressure regulating portions of the torque proportional pressure; a torque signal passage connecting to the variable force solenoid valve means with the pressure regulator valve means whereby the regulated pressure level maintained by the main regulator valve means is controlled in response to changes in the torque proportional pressure; and a variable force solenoid pressure relief valve means communicating with the torque signal passage and with the variable force solenoid valve means whereby the variable force solenoid valve means is adapted to regulate and to develop a pressure of reduced value relative to the regulated pressure of the main pressure regulator valve means as it establishes the torque proportional pressure, the solenoid pressure relief valve means comprising a pressure regulating valve spool, a valve chamber receiving the spool. The spool and the valve chamber having registering valve lands, a valve spring on one side of the spool urging the spool in one direction, a first pressure area on the pool being exposed to the torque proportional pressure, a second pressure area on the valve spool exposed to the pressure of reduced value whereby the spring, the pressure of reduced value and the torque proportional pressure establish a balanced force on the spool.

• Assignee: Ford Motor Co., Dearborn, MI
• Patent Number(s): US 4833946
• OSTI ID: 5526405
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330602* -- Vehicle Design Factors-- Engine-Transmission Matching
AUTOMATION
CONTROL
CONTROL EQUIPMENT
ELECTRIC COILS
ELECTRICAL EQUIPMENT
EQUIPMENT
FLUID MECHANICS
FLUIDS
HYDRAULIC FLUIDS
HYDRAULICS
MACHINE PARTS
MECHANICAL TRANSMISSIONS
MECHANICS
PRESSURE CONTROL
SOLENOIDS
WORKING FLUIDS