In order to explore the influence of noncam valve pattern on the lowload performance of engine, improve volumetric efficiency and reduce gas exchange loss,7 sets of intake profiles were designed by considering the valve response delay and seating impact and multiple intake late closing angles between 10° and 100°ABDC were acquired. Importing noncam intake profile into gasoline engine model, 6 sets of noncam exhaust profiles were designed when the charging efficiency was the highest and the exhaust early opening angle is between 10° and 60°BBDC. In the conditions of 50% load at 1 000 r/min, the influence of noncam valve pattern on gasoline engine performance was further researched. The results indicated that the charging efficiency increased by 9.52% when the intake late closing angle was 20°ABDC. The noncam exhaust profiles were adopted and the exhaust early opening angles were optimized at the same intake phase. At 40°BBDC,the total exhaust loss was the least and the indicated torque increased by 16.88%. At 50°BBDC, the fuel economy was optimal and BSFC was 260.18 g/（kW·h） which improved by 14.91%. Accordingly, adopting the noncam valve pattern and optimizing the intake and exhaust phase could effectively increase the charging efficiency, reduce the exhaust loss and improve the power and economy of engine.
ZHANG Pengbo
,
HE Yituan
,
HONG Yun
,
TAO Youdong
,
YUAN Chenheng
. Low-Load Performance of Gasoline Engine Based on Non-Cam Valve Pattern[J]. Vehicle Engine, 2018
, 0(6)
: 29
.
DOI: 10.3969/j.issn.1001-2222.2018.06.005
