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US 6,527,670 B1Granted
Control device for an automatic automobile transmission
AssigneeZF Friedrichshafen AG
InventorsGeorg Gierer, Uwe Rühringer
Life of this patent
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AssigneeZF Friedrichshafen AG
InventorsGeorg Gierer, Uwe Rühringer
Estimating the term…
An electronic-hydraulic control device of an automatic automobile transmission with frictional clutches or brakes that can be hydraulically operated to shift individual gears (A, B C, D, E), and with an electronic control device (32) which is electrically connected with a lever inside the motor vehicle, shifting gears depending on the preselected lever position and certain parameters of the combustion engine and transmission. If the electronic control device (32) thus de-energizing all solenoid valves (11, 12, 15, 16), an emergency gear is maintained during forward travel until the combustion engine is shut off after which the parking mechanism is automatically engaged, and if the electronic transmission control (32) fails during rearward travel, all clutches or brakes are depressurized and the parking mechanism is automatically engaged. By manually operating a lever (36), a valve (17) is actuated which automatically engages an emergency gear for forward travel and simultaneously unlocks the parking mechanism, with the parking mechanism and forward gear being maintained until the combustion engine is shut off.
An electronic hydraulic control device of an automatic automobile transmission with frictional clutches or brakes (A, B, C, D, E) that can be hydraulically engaged and released to shift individual gears, whose actuators have clutch valves (24, 25) associated with them, with an electronic control device (32) by which a plurality of electrically actuated solenoid valves (11, 12, 15, 16) controlling the actuators can be adjusted depending on operating parameters of the automobile transmission and of a drive motor as well as of a selector lever device, and with a parking mechanism connected with a spring(19) which disengages hydraulically through the control device or manually and which can be locked by the spring(19), wherein by manually unlocking the parking mechanism a parking mechanism valve (17) is hydraulically actuated thereby selecting and engaging a forward gear, wherein the parking mechanism valve (17) is connected to a manual unlocking device (36) and is held in a zero pressure state by the spring (19) so that pressure applied to the parking mechanism valve (17) is not passed on to a hydraulic drive control.
Dependencies are inferred from the claim text.