Hyundai Motor Company

Kia Motors Corporation

Yoonho Cho

Young Kyu Oh

Il Joong Hwang

Chulho Yu

Young-Joon Park

Dongheon Park

Dong Hoon Seok

An engine having a variable valve timing mechanism may include a camshaft having a cam formed thereon for moving an intake or exhaust valve, a variable rotation unit disposed on the same axis with the camshaft to rotate the camshaft to have a retard angle chamber and an advance angle chamber for controlling a retard angle and an advance angle of the camshaft, a variable valve bolt having a fastening portion for fastening the variable rotation unit to the camshaft, and an oil control valve for making selective supply of hydraulic oil to the retard angle chamber and the advance angle chamber, and a valve controller disposed on an outer side of the variable rotation unit for controlling the oil control valve in the variable valve bolt.

Engine having continuously variable valve timing mechanism

A method of controlling a CVVT may include a) checking whether a predetermined time has passed, after engine starts. b) locking an actuator by driving oil control valve with different driving currents in accordance with whether a predetermined time has passed after the engine starts. c) unlocking the actuator or feed-backing control cam phase in accordance with whether the actuator is unlocked. d) feed-backing control cam phase or locking the actuator by driving oil control valve with predetermined current in accordance with whether control cam phase is not reached before the actuator is locked. e) driving the oil control valve with predetermined current to maintain the control cam phase or turning off the oil control valve, after feed-backing control cam phase or locking the actuator by driving the oil control valve with predetermined current in accordance with whether the control cam phase is not reached before the actuator is locked.

Method of controlling CVVT according to current control for oil control valve

A valve system includes a first valve provided on an intake or exhaust port; a second valve provided on another intake or exhaust port; a first cam unit on a camshaft, defining first and second lobe heights; and a second cam unit on the camshaft, defining a third lobe height. The first cam unit moves the first valve by a distance of either the first or the second lobe height, and the second cam unit moves the second valve by a distance of the third lobe height.

Valve system

Growing community of inventors

Whasung-Si, South Korea

Yoonho Cho