寒区缸内直喷发动机机油液面异常增高问题研究

针对缸内直喷车辆在寒冷地区出现的机油液位异常增高问题，对其产生的机理与问题解决方法进行了试验研究.选择三个厂家车辆在黑河地区进行寒区户外实车实验.实验过程中对机油液位、机油温度和冷却水温度等参数变化进行记录.提出以机油液面高度和机油液面升高速率为指标评价各影响因素对机油液面升高问题影响的方法.通过控制变量法，选择适当循环数据对各影响因素效果进行分析.实验结果表明:喷油方式和发动机温升速度是影响机油液位升高的重要因素.通过增加喷射次数、提高发动机温升速度等措施可降低机油液面升高速度，加快机油液面平衡，减小机油液面高度. 

Abnormal Increase of Oil Level in Gasoline Direct Injection Engine at Freezing Area

The increase of oil level is a problem of gasoline direct injection engine at freezing area. The research was carried out to study the mechanism and solution of the problem. Selecting some test vehicles from three different manufacturers,the outdoor experiments were carried out in Heihe district. In the experiment, the change of oil level, oil temperature and cooling water temperature were recorded. Taking the oil level height and oil level rise rate as criterion to evaluate the influencing factors of oil level rise, the main influencing factors of oil level rise were analyzed separately through variable control. The results of the experiment show that the fuel injection mode and temperature rise speed of engine are main reasons of the rise of oil level. The increase of injection times and engine temperature rise speed can reduce the rise rate of oil and speed up the oil level to balance.