Device for relative positional changes of camshaft for variable valve gear of internal combustion engine has locking device which in engine start phase keeps rotor in fixed position between end positions of pressure chambers

摘要

The device for hydraulic relative positional changes of a camshaft for a variable valve gear of an internal combustion engine comprises a rotor (3) enclosing an axial control piston (2), and a stator. A locking device acts between the rotor and stator and pressure chambers are formed between the rotor vanes (4) and stator vanes (6). In the start phase of the engine the locking device (8) keeps the rotor in a fixed position between end positions of the pressure chambers (A,B), and not until after a defined low exhaust gas running of the engine is the locking device unlocked by means of the control piston via a first pressure line (9).