Device for the control of shifting members of automatic change-speed transmissions
AssigneeDaimler-Benz Aktiengesellschaft
InventorsHans-Joachim M. Forster, Georg Eltze, Hans Steinbrenner
Life of this patent
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Abstract
A control system for regulating or controlling the actuating force of shifting elements which in automatically shifted change-speed transmissions act on friction elements that selectively brake, hold fast and release a structural element of such a change-speed transmission as a function of operating parameters; one of the operating parameters which is thereby used in the system of this invention is the predetermined change of the engine rotational speed as a function of time (dn/dt).
Claims41
An installation for the regulation or control of the actuating force of shifting members which in automatically shifted change-speed transmissions act on friction elements that selectively brake, hold fast, and release a structural element of such a change-speed transmission in dependence on operating parameters of a vehicle, characterized by a control system for controlling said actuating force including control means for varying sid actuating force as a function of at least one operating parameter corresponding to a desired change of engine rotational speed as a function of time (dn/dt), and means for calculating the desired dn/dt in accordance with other vehicle parameters, the control means controlling the oil pressure which serves as an actuating force of the shifting member, said control means varying the oil pressure from an upper level to a lower level and causing the oil pressure to drop from the upper level to below the lower level and then rise to the lower level at the beginning of a shifting operation.
An installation for the regulation or control of the actuating force of shifting members which in automatically shifted change-speed transmissions act on friction elements that selectively brake, hold fast, and release a structural element of such a change-speed transmission in dependence on operating parameters, characterized by a control system for controlling said actuating force including control means for varying said actuating force as a function of at least one operating parameter corresponding to a predetermined desired change of engine rotational speed as a function of time (dn/dt), means for producing the desired value of dn/dt and means for producing an existing value of dn/dt, said control means including a control circuit means having an adding means controlling a respective shifting member, said adding means having several inputs, one input being connected with a first switching means which applies to the one input of the adding means in one position a voltage corresponding to at least one parameter and in its other position said last-mentioned voltage reduced by a predetermined amount, another input of the adding means being controlled by a control amplifier means having several inputs, one input of said control amplifier means being controlled by the existing value of dn/dt and another input thereof being controlled by the desired value of dn/dt.
Dependencies are inferred from the claim text.