VARIABLE VALVE LIFT SYSTEM IN ENGINE AND CONTROL METHOD THEREOF

摘要

A variable valve lift (VVL) system in an engine includes an oil control valve and a lock pin configured to be hydraulically actuated against an elastic force of a return spring under a control of the OCV. An orifice through which oil passes is formed to supply hydraulic pressure to the OCV and the lock pin. An oil pressure sensor measures the hydraulic pressure to be supplied to the OCV and the lock pin. A controller is configured to receive a signal from the oil pressure sensor and to control the OCV according to the received signal.

主权项

1. A variable valve lift (VVL) system in an engine, including:
an oil control valve (OCV); a lock pin configured to be hydraulically actuated against an elastic force of a return spring under a control of the OCV; an orifice through which an oil passes to supply a hydraulic pressure to the OCV and the lock pin; an oil pressure sensor measuring the hydraulic pressure to be supplied to the OCV and the lock pin; and a controller configured to receive a signal from the oil pressure sensor and control the OCV according to the received signal, wherein the orifice has a size that is capable of securing a minimum hydraulic pressure necessary to implement a hydraulic lash adjuster function and lubrication of frictional parts in an operation area of the engine in which the hydraulic pressure is able to be supplied at a maximum rate, wherein the controller is configured to turn on the OCV when the measured hydraulic pressure received from the oil pressure sensor does not reach a pressure level such that the hydraulic pressure is applied to the lock pin, the lock pin is able to overcome the elastic force of the return spring, and wherein the controller is further configured to forcedly turn on the OCV when the measured hydraulic pressure acting on the lock pin is lower than the elastic force of the return spring which elastically supports the lock pin.