张腾1，刘宁2，韩文涛1*，许自顺2，郑碧莹3，朱耀文1，刘冠麟1
1.潍柴动力股份有限公司，山东 潍坊 261061；2.一汽解放青岛汽车有限公司，山东 青岛 266000；
3.潍柴动力空气净化科技有限公司，山东 潍坊 261061
摘要：为提高某天然气发动机制动性能，保证行车安全，在对不同发动机辅助制动形式进行分析及研究的基础上，确定采用缸内压缩释放制动的辅助制动形式；对装有缸内压缩释放制动的天然气发动机进行试验，测试气门升程、凸轮轴挺杆接触应力及发动机制动功率等参数，并对比同排量柴油机和天然气发动机的制动功率;进行整车道路试验，测试搭载缸内压缩释放制动系统天然气发动机的车辆制动性能。结果表明：天然气发动机装有缸内压缩释放制动系统可以有效增加制动功率，使车辆在下坡过程中车速降低、可控；天然气发动机制动功率比同排量柴油机小9.3%；采用脚踏板制动-缸内压缩释放制动形式，脚踏板使用频率较单脚踏板制动减少68%，较脚踏板制动-排气蝶阀制动减少58%；压缩释放制动系统能够有效延长车辆下坡行驶时间，制动更安全。
关键词：天然气发动机；缸内压缩释放制动；气门升程；接触应力；制动功率
Abstract：In order to improve the braking performance of a natural gas engine and ensure driving safety, based on the analysis and study of different engine auxiliary braking methods, the compression release braking in cylinder is determined.The parameters such as valve lift, contact stress of camshaft tappet and engine braking power are tested on a natural gas engine equipped with in cylinder compression release brake, and the braking power of diesel engine and natural gas engine with the same displacement are compared. The vehicle road test is also carried out to test the braking performance of in-cylinder compression release braking system. The results show that the natural gas engine equipped with cylinder compression-release braking system can effectively increase the braking power, reduce the vehicle speed and controllable in the process of downhill. The braking efficiency of natural gas engine is 9.3% less than that of diesel engine with the same displacement. Using pedal brake-cylinder compression release brake, the use frequency of the pedal brake is 68.1% less than that of the pedal brake only, 57.8% less than that of the pedal brake-exhaust butterfly valve brake. The compression release braking system effectively prolongs the downhill driving time of the vehicle and makes braking safer.
Keywords:natural gas engine;cylinder compression release brake; valve lift;contact stress;brake power
|
