ELECTRO-HYDRAULIC VARIABLE VALVE LIFT APPARATUS

摘要

PURPOSE: An electric-hydraulic VVL(variable valve lift) device is provided to prevent shock and vibration due to opening/closing of a valve since a second shock reducing oil path is opened/closed by a guide protrusion. CONSTITUTION: An electric-hydraulic VVL device comprises a valve unit housing(10), a main piston(20), a main spring(30), a slave piston(40), and a main oil supply unit(50). A guide protrusion unit(15) is formed in the valve unit housing. The main piston is installed in the valve unit housing. The main piston forms an oil chamber(25) with the valve unit housing. The main spring is installed in the oil chamber. The main spring elastically supports the main piston. The slave piston is guided along the guide protrusion unit in the valve unit housing. The slave piston reciprocates according to the reciprocating movement of the main piston to open/close a valve. The main oil supply unit supplies fluid pressure to the oil chamber.