Patent ID: 7487752
Filing Date: 2009-02-10
Classification: F01L,F15B,F16K,Y10T

Abstract:
1. A control valve for a device to modify the timing of an internal combustion engine, comprising a valve housing having a generally hollow-cylindrical shape, a control piston arranged inside the valve housing and axially displaceable therein, a hydraulic connector on the housing, two operative connectors on the housing, at least one reservoir connector on the housing, with the operative connectors being connectable to the hydraulic connector and the reservoir connector by way of an axial displacement of the control piston inside the valve housing, and a filter arranged between the hydraulic connector and the operative connectors, wherein the control piston is hollow with an interior thereof communicating with one of the operative connectors depending on a position of the piston and communicating with the hydraulic connector via two openings in an outer surface of the control piston independently from a position of the piston, and the filter is arranged inside the control piston and has a cylindrical surface arranged in an area of the two openings.