Patent ID: 7841361
Filing Date: 2010-11-30
Classification: F01L,F16K,Y10T

Abstract:
1. An electromagnetic hydraulic valve controlling a device for a rotational angle adjustment of a camshaft relative to a crankshaft of an internal combustion engine, comprising: an electromagnet having a hollow-cylindrical magnet housing, at least one coil winding, an axially moveable magnet armature, and a first and a second pole shoe; and a valve part having a hollow-cylindrical valve housing in which is accommodated a control piston which can be moved axially by the magnet armature of the electromagnet via a plunger rod, with pressure medium connections being formed in the valve housing, which pressure medium connections can be connected to or separated from one another as a function of the position of the control piston, and with a return of the control piston being affected by a pressure spring which acts counter to a force of the magnet armature, wherein a sleeve, which is composed of a base and a hollow-cylindrical side wall, is arranged on an end of the control piston which is situated in a direction of the plunger rod, and the sleeve has a greater hardness than the control piston, and wherein the hollow-cylindrical side wall of the sleeve has, at an end remote from the base, a flanged edge which has a smaller wall thickness than the hollow-cylindrical side wall.