Camshaft adjustment device
AssigneeDaimler AG
InventorsEnrico Paul, Uwe Reuter, Holger Rudzinski, Ulrich Stubbemann
Life of this patent
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Abstract
In an adjustment device for adjusting the phase position of a camshaft relative to a crankshaft of an internal combustion engine which includes a hydraulic system for supplying hydraulic fluid under pressure to the adjustment device for the controlled admission to, and release thereof from, operating chambers of the adjustment device under the control of a control device including a control valve, the operating chambers are in communication with one another via control valves to permit flow of hydraulic fluid from one set of operating chambers to another by the varying torques effective on the camshaft or by controlling fluid supply to the operating chambers from the hydraulic fluid supply system.
Claims18
An adjustment device for adjusting the phase position of camshaft (1) with respect to a crankshaft of an internal combustion engine which includes a hydraulic system (40) for supplying hydraulic fluid to the adjustment device, comprising:
- an adjustment structure including operating chambers (4a-4d, 5a-5d), a control arrangement (42) including a control valve (6) for controlling the flow of hydraulic fluid to, and from, the operating chambers (4a-4d, 5a-5d), and a flow passage interconnecting the various operating chambers under the control of the control valve (6), said hydraulic system (40) including a pressurized hydraulic fluid supply line with a first check valve (10) arranged in a pressurized hydraulic fluid supply line (9) and the flow passage interconnecting the operating chambers (4a-4d, 5a-5d) including a second check valve (15), and a serial valve (19) connected to the control valve (6) for switching the adjustment device between a first operating mode, in which the camshaft is adjusted passively by changing camshaft torques, and a second operating mode, in which the camshaft is adjusted actively by controlling the admission of pressurized hydraulic fluid from a pressurized hydraulic fluid source to, and the release of the hydraulic fluid from, the operating chambers (4a-4d, 5a-5d).
Dependencies are inferred from the claim text.