Hydraulic control system for servos in automatic transmissions

US4345489A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Alfred Muller · Krefeld, DE
• Manfred Schwab · Gerlingen, DE
• Meinrad Feder · Leonberg, DE
• Achim Schreiber · Schwieberdingen, DE
• Joseph Sauer · Strullendorf, DE

Key dates

• Filing date: Jan 14, 1980
• Grant date: Aug 24, 1982
• Expiry date: Jan 14, 2000

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16H2061/0258
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

The invention pertains to a hydraulic control system for servos in automatic transmissions, which, in a known fashion, utilizes a main pressure valve to regulate the pressure within the control system and further utilizes a converter pressure valve to supply a hydrodynamic torque converter and the lubrication system. The servos (for example, the clutches) utilized in this type of automatic transmissions cooperate with electromagnetically actuated pressure regulating valves have a current-proportional response. These electromagnetic valves are actuated by electronic control signals generated by sensors which monitor various parameters during operation, making previously utilized sensors superfluous. By control of the pressure regulating valves the forward gear, the reverse gear or the neutral gear can be engaged in the simplest fashion. By means of a magnet valve associated with the main pressure valve the levels of pressure may be varied. It is also possible, via simple associated elements, to install an emergency system which during a failure of the electrical system allows the transmission to continue to operate.