Simulation and experimental research of hydraulic pressure and intake valve lift on a fully hydraulic variable valve system for a spark-ignition engine

Fei Chen,Xiaorui Li,Tingting Sun,Yingjie Chang,Zongfa Xie,Kaiyu Zhang,Yuzhen Huang

doi:10.1177/1687814018773156

Abstract

A fully hydraulic variable valve system based on spark-ignition engine BJ486EQ is introduced in this article, which can provide fully variable valve lifts, valve timing, and valve opening duration....

Highlights

Variable valve technology (FVVT) can achieve continuous variation of the maximum valve lift, valve opening duration, and valve timing.[1,2] Pumping loss is the main issue of the spark-ignition (SI) engine because of the traditional throttle-based load control, which makes low efficiency of SI engines
The intake valve opening duration will continue to increase, while the maximum intake valve lift remains unchanged with the increase in the oil relieving angle when the intake valve lift reaches the maximum designed value
Intake valve lift and pressure of the hydraulic tappet chamber are shown in Figure 9 when the engine speed is 3000 r/min and the oil relieving angle is 100°CA ATDC

Summary

Introduction

Variable valve technology (FVVT) can achieve continuous variation of the maximum valve lift, valve opening duration, and valve timing.[1,2] Pumping loss is the main issue of the spark-ignition (SI) engine because of the traditional throttle-based load control, which makes low efficiency of SI engines. Many researchers have developed different kinds of designs of which some are used in commercial cars This technology can control loads without the throttling valve and reduce the pumping loss.[11,12] most of them cannot provide fully variable valve timing, and too many parts are involved in the valve movement, which makes the mechanism too complex, and mechanical energy loss is big under. A stepping motor that is mounted on the cylinder head cover drives the motor shaft in order to make the gear sector and the valve sleeve gear shown in Figure 2 mesh to adjust the oil relieving angle of the oil relieving valve.

Methods

Results

Conclusion