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AssigneeRobert Bosch GmbH
InventorsAlfred Muller, Manfred Schwab, Meinrad Feder, Achim Schreiber, Joseph Sauer
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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.
A hydraulic control system for a plurality of switching elements of an automatic transmission including a main conduit, a main pressure valve to regulate the pressure in the main conduit and a torque converter valve, comprising a plurality of electromagnetically actuated pressure regulating valves connected in parallel to said main pressure conduit, each pressure regulating valve having a corresponding variable fluid opening, the variation of said opening being proportional to applied electrical current, and each switching element being connected to the main pressure
Dependencies are inferred from the claim text.