文档介绍：Industry 启动的保证-内燃机油低温性能,试验与标准壳***术部 Dec 2007 Industry 内容提要?发动机油与发动机启动的关系?规格要求与实验方法简介?发动机油低温流变特性与发动机润滑特性对应关系?发动机油低温性能要求与台架试验–CCS (冷启动模拟试验) –MRV (微转粘度计测试) –MRV TP-1 (改进的微转粘度计测试) –SBT (扫描布氏凝胶指数测定法) ?发动机油低温粘度标准与台架试验 Industry 发动机的启动条件与润滑油的影响足够的发动机启动转速发动机启动需要怎样的条件? ?合适的燃烧室温度?足够的气缸压缩压力?高浓度高质量的混合气?点火提前和正确的配气=启动转矩–发动机内阻(120-200rpm min) ?电瓶能量(低温影响) ?启动马达?电气系统状况?活塞环与缸套的摩擦?压缩行程阻力?旋转部件的阻力(凸轮轴, 阀系等) ?发动机附件, 如风扇,发电机, 水泵等当发动机启动时,机油在减小发动机内阻方面起到至关重要的作用 Industry 发动机油低温启动性能的关注点加油口摇臂机油回路活塞及活塞环连杆连杆大头主轴承机油油底壳(机油盘) 集滤器机油滤清器机油泵主油道通往缸盖的油道气门座及气门弹簧连杆轴承机油低温泵送性: ?阀系及凸轮轴的润滑?主油道压力的建立?低温泵送粘度低温动力粘度: 润滑油低温情况下启动时在活塞环与气缸套处流变行为。 Industry API Engine Oil Classifications 2004 SAE Low Temperature ( 癈) Cranking Viscosity (3), mPa-s Low Temperature ( 癈) Pumping Low-Shear-Rate Low-Shear-Rate High-Shear-Rate Viscosity Grade Max Viscosity (4), mPa-s Kinematic Viscosity (5)(mm2/s) at 100 癈 Kinematic Viscosity (5)(mm2/s) at 100 癈 Viscosity (6) (mPa-s) Max with Min Max at 150癈 No Yield Stress (4) Min 0W 6200 at -35 60000 at -40 - - 5W 6600 at -30 60000 at -35 - - 10W 7000 at -25 60000 at -30 - - 15W 7000 at -20 60000 at -25 - - 20W 9500 at -15 60000 at -20 - - 25W 13000 at -10 60000 at -15 - - 20 - - < 30 - - < 40 - - < (0W-40, 5W-40, 10W-40 grades) 40 - - < (15W-40, 20W-40, 25W- 40, 40 grades) 50 - - < 60 - - < SAE Viscosity Grades For Engine Oils (1)(2) (1)Notes-1cP = 1mPa-s; 1 cSt = 1mm 2/S (2) All values are critical specifications as defined by ASTM D3244 (see text, Section 3). (3) ASTM D5293 Reprinted with persmission form SAE J300? 2004 Society of Automotive Engineers, Inc. (4) ASTM D4684: Note that the presence of any yield stress detectable by this method constitutes a failure regardless of viscosity. (5) ASTM D445 (6) ASTM D4683, CEC L-36-A-90 (ASTM D4741) or D5481Industry 低温测试方法 API SJ 及以上要求 Industry 内燃机油的低温启动性能?50年代认为内燃机的最高边界启动粘度为 3000-5000 . ?经过大量的车队试验得出。?单级机油被认为是典型的牛顿流体(剪切速率不影响粘度)。?以双对数坐标