Patent ID: 7819098
Filing Date: 2010-10-26
Classification: F01L,F02D,Y02T

Abstract:
1. A variable valve timing device that delivers rotation of a crankshaft to a first camshaft, and to a second camshaft through the first camshaft, comprising: a first variable valve timing unit for changing a phase of the first camshaft; a second variable valve timing unit for changing a phase of the second camshaft; a crankshaft sensor that senses angle changes of the crankshaft; a camshaft sensor that senses angle changes of the second camshaft; and a control portion for controlling the phase of the second camshaft by controlling the second variable valve timing unit, or controlling the phases of both camshafts by controlling the first variable valve timing unit, according to signals from the crankshaft sensor and the camshaft sensor, wherein the control portion selects one of a plurality of modes and controls the camshafts according to the selected mode, wherein the modes comprise: a first mode in which the phase of the second camshaft is retarded and the phases of both camshafts are adjusted by adjusting the phase of the first camshaft; a second mode in which the phase of the second camshaft is advanced and the phases of both camshafts are adjusted by adjusting the phase of the first camshaft; a third mode in which the phase of the first camshaft is advanced and the phase of the second camshaft is adjusted; and a fourth mode in which the phase of the first camshaft is retarded and the phase of the second camshaft is adjusted.