Hydraulic system for an automatic transmission of a motor vehicle
AssigneeAudi AG
InventorMathias Weinhardt
Life of this patent
Estimating the term…
Abstract
A hydraulic system for an automatic transmission of a motor vehicle. A high pressure circuit in which a pressure accumulator, at least one clutch as well as gear selectors and at least one hydraulic pump are arranged, which can be controlled by an electronic control unit. The pressure accumulator can be connected to a hydraulic positioning cylinder via at least one hydraulic path, wherein a control valve that can be controlled by the control unit is arranged upstream thereof, with which a hydraulic pressure at the hydraulic positioning cylinder can be adjusted, and which control valve can be moved between two through-flow positions in order to move a piston in opposing piston strokes via opposing piston travel paths as well as piston speeds in the hydraulic positioning cylinder.
Claims11
A hydraulic system for an automatic transmission, in particular a dual-clutch transmission, of a motor vehicle, comprising:
- a high-pressure circuit, in which a pressure accumulator, at least one clutch, and gear selectors and at least one hydraulic pump are arranged, which is operated via an electronic control unit, wherein the pressure accumulator is connected via at least one hydraulic path to a hydraulic positioning cylinder, from which a control valve that can be operated by the control unit is connected upstream, wherein the control valve can adjust a hydraulic pressure applied to the hydraulic positioning cylinder, which control valve can be adjusted between two flow-through positions in order to displace a piston in opposing piston strokes via opposing piston positioning distances and piston speeds in the hydraulic positioning cylinder, wherein each piston stroke is linked to a hydraulic fluid removal from the hydraulic system, wherein the control unit includes a diagnostic module for performing delivery volume flow diagnosis, during which an analysis unit determines an actual delivery volume flow and compares the actual delivery volume flow to a target delivery volume flow and, if there is a significant deviation, diagnoses a fault which is stored in a delivery volume flow fault memory.
Dependencies are inferred from the claim text.