摘要
目前250ml排量以下的小型高速汽油机是中国两轮摩托车产品使用的主要动力源,但该系列发动机中低速性能欠佳,主要表现为低速扭矩小,中速油耗高,高速功率小且最大功率点对应的转速略小,因此全面改善并提高汽油机的性能成为亟需解决的关键技术问题。论文利用先进的可变配气正时技术与双火花塞快速燃烧技术,以某型125ml摩托车汽油机为代表,综合实际工况和使用特点,研发了一种基于双火花塞点火并适应多工况的三段式速燃VVT系统。
论文的主要研究内容如下:
①研究并设计了一种基于双火花塞点火并适应多工况的三段式速燃VVT系统。该系统采用三进气凸轮与三进气摇臂、进气摇臂自动切换与双火花塞点火控制系统、外接油路系统与对称布置的双火花塞,可实现多工况配气定时优化和双火花塞按工况自动实现单点火或同相点火,或异相点火。
②结合三段式双火花塞速燃多工况VVT系统结构特点对小型高速汽油机进行改型设计,综合运用二次空气喷射系统、双级催化转化器与曲轴箱闭式通风装置,将排气污染物控制在GB14622—2007排放限值内,实现某型125ml汽油机排放强化控制。
③利用AVL-TYCON软件对三段式双火花塞速燃多工况VVT系统进行运动学与动力学分析,包括对进气门升程、进气门速度及加速度、三进气凸轮与三进气摇臂在不同转速下的接触力、接触应力、气门落座力、气门内外弹簧的运动及受力情况等进行仿真分析;利用ANSYS软件对三段式双火花塞VVT系统中的关键零部件——低速进气摇臂、中速进气摇臂与高速进气摇臂进行有限元分析,验证三段式双火花塞速燃多工况VVT系统运行的合理性。
④针对汽油机燃烧模型处理准则,利用蒙特卡罗原理,建立有限平面逼近法。与常用的平面节点积分法和球面三角形法进行综合比较,把平面节点积分法和球面三角形法规整为有限平面逼近法的特例,实现了三种方法的统一;利用有限平面逼近法研究双火花塞单点火和同相点火等不同燃烧工况。
⑤利用AVL三维仿真软件FIRE对某型单缸125ml小型高速汽油机进行进气过程与燃烧过程仿真分析,为优化燃烧控制策略奠定基础。
⑥通过某型单缸125ml原型机与装有三段式双火花塞速燃多工况VVT系统汽油机的外特性试验和工况法试验,对怠速、低速、中速、高速等不同运转工况进行综合性能分析,验证分析的正确性。
Small and high-speed gasoline engines below 250ml displacement are the main power of Chinese two-tyre motorcycles, but their performance is not very good at low and medium speed. These problems are small torque at low-speed, high fuel consumption at medium speed, small power at high speed and low speed at maximum power point. Therefore, it is necessary to improve the engine performance.
In this paper, according to actual working condition and use characteristics of a normal 125ml gasoline engine, a VVT system of triple-form and rapid combustion with dual-spark plug ignition for multiple states is developed with advanced technologies of Variable Valve Timing and rapid combustion with dual-spark plugs.
The main contents are illustrated as follows.
①One multi-state VVT system of triple-form with dual-spark plug ignition is researched and designed, which adopts three admission cams and rockers, an automatic switching control system, an external switch oil system and dual-spark plugs set symmetrically to realize multi-state Valve Timing Optimization and single or dual-spark plug ignition in or out phase automatically according to the working condition to optimize intake and promote combustion.
②Combining the structure characteristics of the VVT system of triple-form with dual-spark plugs, a small and high speed 125ml gasoline engine is retrofit with the auxiliary air injection system, the two-stage catalytic converter and a closed crankcase ventilation device to decrease exhausted pollutants in the GB14622-2007 emission limit to further control the emission.
③A VL-TYCON software is used to analyze the kinematics and dynamics of the VVT system of triple-form and dual spark plugs including the simulation and calculation on the intake valve lift, speed and acceleration, force and stress of three intake cams and rockers at three different speeds, force of valve closed and movement and force of inside and outside valve springs. In addition, the finite elements of the key components as intake rocker arms at low, medium and high speed are analyzed with the ANSYS software to verify operation rationality of the system.
④According to the treatment benchmark of the gasoline engine combustion model, a limited planar approximation method is created to calculate the combustion model with Monte Carlo principle. The limited planar approximation method is compared with the plane nodes method and spherical triangle method on calculation units, accuracy and amount, and the two latter are proved to be the special cases of the former to unify the three methods. Then the combustion conditions of the single and dual spark plug ignition in phase are calculated with the method.
⑤The intake and the combustion processes of the small gasoline engine that is 125ml displacement with one cylinder are simulated and analyzed with the AVL-FIRE software of three-dimensional simulation to optimize the combustion controlling strategy.
⑥The correctness of the analyzing method is proved by testing engine performance for wide open throttle and mode test cycle between the 125ml prototype engine with one cylinder and the VVT gasoline engine in different working conditions including the idle, low, medium and high speeds.
引文
[1]汤兆平,孙剑萍.汽油机技术如何面对世界石油危机[J].拖拉机与农用运输车, 2006,12:3-4.
[2]赵昌普,何勇灵.面对日益严峻的能源及环境问题论内燃机的发展方向[J].小型内燃机与摩托车, 2001,35(5): 44-46.
[3]于曰桂.我国摩托车技术发展现状及前景[J].摩托车技术, 2000,(5):3-6.
[4] JH150T/JH125E型摩托车维修手册[M].重庆:中国嘉陵工业股份有限公司, 1997.
[5]中国汽车工业协会. 2008年摩托车工业综合分析[M].中国汽车工业协会(摩托车)综合信息, 2009,2:1-4.
[6]柯亚仕,蒋德明.可变气门定时研究的回顾及展望[J].车用发动机, 1996,(1):1-6
[7]苏岩,李理光,肖敏等.可变配气相位对发动机性能的影响[J].汽车技术, 2000(10):10-14.
[8] Michae Grohn, Klaus Wolf. Variable valve timing mechanisms[C]. SAE891990.
[9]于京诺,陈燕,王昕彦.汽车稀薄燃烧技术[J].汽车与船舶, 2004(10):79-83.
[10] Heywood J B著,范希才译.最佳性能点燃式发动机的燃烧室设计[M]. Vehicle Design,1984,5(3):26-30.
[11]苏岩,李理光,肖敏等.国外发动机可变配气相位研究进展—机构篇[J].汽车技术, 1999(6):10-14.
[12]高村直己.年鑑/二輪車エンジン[J].自动车技术, 2000(54):8.
[13]王冰,艾曦峰,李德才. VTEC发动机与VVT-I发动机工作原理对比研究[J].黑龙江交通科技, 2007(8);90~92.
[14] Kenji Shibano, Shinji Samimaru, Takemasa Yamada, etal. A newly developed variable valving mechanism with low-mechanical friction[C]. SAE920451.
[15] Peter Kreyuter, Peter Heuser, Michael Schebitz. Strategies to improve SI-Engine performance by means of variable intake lift, timing and duration[C]. SAE920449.
[16] Michael M.Schechter, Michael B.Levin. Camless English[C]. SAE960581.
[17]邵显龙.可变配气机构的种类、构造和未来动向[J].汽车技术, 2001(4):20-23.
[18]王文惠,李剑虹.可变配气相位机构的研究[J].内燃机工程, 1996,17(1):29-34.
[19]苏进辉.摩托车发动机VVT系统控制策略研究[D].重庆大学, 2006.
[20]北條敦雄.年鑑/二輪車エンジン[J].自動車技術, 2001(55):8.
[21]吴俊刚.中小排量摩托车发动机VVT机构的研制[D].重庆大学, 2005.
[22] Huangqi, Zhang Li. Research on a VVT Mechanism of Switching Cam Profile for MotorcycleEngine[M]. 2005 the Seventh China and korea International Conference on Internal Combustion Engines and Automotive Engineering April 20-25,2005 Huangzhou,China.
[23]贾元华,宋世忠,姚喜贵.点燃式发动机快速燃烧与新型快速燃烧室的研究设计[J].农机化研究, 1998,2:44-42.
[24]何学良,李疏松.内燃机燃烧学[M].北京:机械工业出版社, 1990.104-144.
[25]蒋德明.内燃机燃烧与排放学[M].西安:西安交通大学出版社, 2001.135-137.
[26]刘瑞林,刘仪,刘巽俊,康展权,吴荣山,马枫.车用汽油机实现快速燃烧的途径[J].内燃机工程, 1993,1(14):17-22.
[27]刘志强,李岳林,汪长军.关于火花点火发动机预混燃烧若干问题的研究进展[J].小型内燃机与摩托车, 2002,31(5): 42-45.
[28]刘瑞林,刘巽俊,康展权,吴荣山,王光一,马枫.提高燃烧速率对发动机性能的影响[J].汽车技术, 1991,(12):18-21.
[29] Miehael Czekala and Brien Johnston. Matching Ignition System Multi-Spark Calibration to the Burn-Rateo fan Engine to Extend Ignitability Limits[C]. SAE981046.
[30]吴锋.双火花塞点火新技术[J].摩托车发动机, 2005.1:13-14.
[31]王伟. CA498柴油发动机配气机构设计[J].汽车技术, 2000,(7):12-17.
[32]盛建军.高速发动机配气机构的运动学分析[J].江苏理工大学学报, 1996,17(2):20-26.
[33]苏军,申屠淼.顶置凸轮配气机构气门升程的精确计算[J].内燃机学报, 1999,17(2):202-204.
[34]谢宗法,张小印等.顶置凸轮机构气门理论运动规律的精确计算[J].内燃机工程, 2007,28(1):20-23.
[35] Noboru Hikosaka. A View of Automotive Diesel Engines[C]. SAE972682.
[36] AVL-BOOST USER GUIDE[M].上海:AVL公司, 2008.
[37] Hong H, Parvate-Patil G B. Gordon B. Review and analysis of variable valve timing strategies-eight way to approach[C]. Proc. Instn Mech. Engrs Vol.218 Part D: J. Automobile Engineering, 2004, 1179-1199.
[38]李惠珍,袁兆成,乐俊秉.配气凸轮设计的进展[J].内燃机工程, 1989,10(1):32-37.
[39]吴广全,李惠珍,陆孝宽.汽车发动机配气凸轮型线优化设计[J].吉林工业大学学报, 1990(2):48-54.
[40]李惠珍,高峰.配气凸轮型线动态优化设计[J].内燃机学报, 1990,8(4):329-336.
[41]邸立明,詹长书.新型连续可变气门正时及升程复合凸轮设计[J].小型内燃机与摩托车, 2006,35(2):19-21.
[42]廖祥兵,王军,张立军.顶置凸轮轴凸轮型线的优化设计[J].内燃机学报, 2001,19(6):588-593.
[43] AVL TYCON USER GUIDE[M].上海: AVL公司, 2008.
[44]郭磊,褚超美,陈家琪.高次多项式凸轮型线特性参数对配气机构性能影响的研究[J].内燃机工程, 2005,26(1):20-23.
[45]袁银南,陈广晖.发动机凸轮升程光顺时不同方法的应用[J].内燃机工程, 1998,19(3):1-6.
[46]袁银南,邵凤楼.用数值分析法提高发动机配气凸轮型线的精度[J].农业机械学报, 1996,27(3):109-114.
[47] R.C.Johnson. Method of Finite Differences Provides Simple but Flexible Arithmatical Techniques for Cam Design[J]. Mach.Design. Nov,1955.
[48]廖晓山.汽车发动机配气机构[M].长春:吉林人民出版社, 1981.
[49]万欣,林大渊.内燃机设计[M].天津:天津大学出版社, 1988.
[50] Adams D R(朱仁文译).配气机构的设计研究[J].国外内燃机, 1993,(1):23-34.
[51]陆际清,沈祖京.汽车发动机设计[M].北京:清华大学出版社, 1993.
[52] David J W,Wei Y,Covey J A. Optimal Rocker Arm Design in High Speed Internal Combustion Engines[C]. SAE 942501.
[53] F.Y.Chen.Mechanics and Design of Can Mechanisms[M]. Pergamon Press.New York,1982.
[54]黄琪,张力等.小型高速摩托车发动机排放控制的强化[J].重庆大学学报(自然科学版), 2006,29(7):15-18.
[55]梁荣光,简弃非,刘勇军,罗胜平.补偿空气法改善汽油机性能的试验研究[J].华南理工大学学报(自然科学版), 1999, 27(9):6-10.
[56]吴锋,马成杰,张锋.应用二次空气结合催化转化器减轻摩托车发动机排放的试验研究[J].内燃机工程, 2004,25(3): 64-67.
[57]张付军,韩恺,刘波澜,段晓波. JS125-12A摩托车二次空气喷射系统的仿真[J].北京理工大学学报, 2005,25(4):298-302.
[58]蔡锐彬,王辉,林慧斌.车用汽油机排放净化装置的研究[J].车用发动机, 2004,10 (5):32-35.
[59]陈国英,廖宪彪.中小功率汽油发电机数字式电子调速器的设计[J].木工机床, 2005,3:25-29.
[60]杨仕,何培祥,鲜继凯.一种汽油发电机组电子调速器[P].中国专利: 200720124861,2008-5-21.
[61]赵铮. Honda GX31汽油机电子调速器的研究[D].重庆:重庆大学车辆工程系, 2003.
[62]于正林,苏成志,曹国华等. AVR单片机原理及应用[M].长沙:国防工业出版社, 2009,4.
[63]何新军.汽油发电机调速系统模糊自适应PID控制[D].重庆:重庆大学,2008.
[64]海涛. ATmega系列单片机原理及应用[M].北京:机械工业出版社, 2008:145-150.
[65] Atmel Corporation. 8-bit AVR Microcontroller with 8K Bytes In-System Programmable Flash[EB/OL]. http://www.iccavr.com/down/View.asp?SoftID=3887, 2007-7-19.
[66]耿德根,宋建国,马潮等. AVR高速嵌入式单片机原理与应用[M].北京:北京航空航天大学出版社, 2003,9.
[67]肖宇峰,黄玉清. AVR嵌入式单片机接口技术与应用[J].兵工自动化, 2003,22(5):41-44.
[68]杨长圣.小功率汽油发电机组数字电子调速器的研究[D].武汉:武汉理工大学自动化系, 2006.
[69]李为监,吴金源.气阀系统多质量模型的数学处理[J].复旦学报(自然科学版), 1982.21(2):131-139.
[70] Takashi Kosugi and Tetsuya Seino. Valve Motion Simulation Method for High-Speed Internal Combustion Engines[J]. SAE Paper 850179, 1985.
[71] YoungKeun Park, Katsuhiko Wakabayashi, Yasuhiro Honda et al.A New Simulation of Dynamic Motion of Engine Valve Train System Using Transition Matrix Method[J]. JSAE Paper 9935383,1999.
[72] Andi Isra Mahyuddin and Ashok Midha.Direct Numerical Solution Algorithm for Parametric Vibration Response and Stability Determination of Mufti-Degree-Freedom Flexible Cam-Follower Systems[J]. JSAE Paper 9531714, 1995.
[73] Yan Hong-Sen, Cheng Wen-Teng. Curvature analysis of spatial cam-follower mechanisms[J]. Mechanism and Machine Theory 34 (1999):319-339.
[74] Lee, Jongmin. Dynamic modeling and experimental verification of a valve train including lubrication and friction[D]. The University of Michigan,1993.
[75]刘尔铎,李慧珍.内燃机配气机构动力分析的多柔体动力学模型[J].汽车工程, 1991,13(4):249-256.
[76]吴国辉. JYM154FMI发动机配气机构仿真分析及凸轮型线设计研究[D].重庆大学, 2008.
[77] S Melaughlin and I Haque. Development of a Mvlti-body Simulation Model of a Winston Cup Valvetrain to Study Valve Bounce[J]. Proceedings of the Institution of Mechanical Engineers, 216: 237-246.
[78] H.K wakenack and J.Smit. Minimum Vibration Cam Profiles[J]. Journal of Mechanical Engieering Science,1968.
[79]刘锦阳,朱本华.汽车发动机气门机构的运动学分析[J].机械科学与技术, 1998,17(2):265-267.
[80]浦耿强,张云清.顶置凸轮配气机构仿真分析[J].汽车科技, 2001, (1):18-10,18.
[81]杨东武.柔性多体系统动力学的建模研究[D].西安:西安电子科技大学出版社, 2005.
[82]许道彦,丁贤华.高速柴油机概念设计与实践[M].机械工业出版社, 2003.
[83]刘忠民,俞小莉,沈瑜铭.配气机构动力学模型的比较研究[J].浙江大学学报(工学版), 2005,39(12):1941-1945.
[84]张效工,陈法成.内燃机气门落座特性的研究[J].内燃机工程, 1980,(2):23-35.
[85]刘忠民.配气机构动力学试验方法与模型规划研究[D].浙江:浙江大学, 2005.
[86]张立梅,张克刚.配气机构振动的研究[J].内燃机工程, 1986,7(3):68-76.
[87] Phlips P J, Schamel A R, Meyer J. An efficient model for valve train and spring dynamics[C]. SAE890619.
[88] H. Y. Isaac Du. Dynamic analysis of a 3D finger follower valve train system coupled with flexible camshafts[J].SAE Paper,2000-01-0909.
[89]史绍熙.内燃机燃烧研究的现状和动向[J].西安交通大学学报, 1994,28(5):31-40,72.
[90]沈颖刚,王宇琳,郑伟,申立中,韦静思.内燃机燃烧过程数值模拟技术发展概况[J].拖拉机与农用运输车, 2004(1): 7-9.
[91]李绍安,苏万华.内燃机燃烧模型的研究现状与展望[J].车用发动机, 1998(2):1-6.
[92]李云清,钱耀义,于秀敏.利用球面三角建立通用的汽油机燃烧室几何模型[J].内燃机学报, 1992,10(3):245-249.
[93]李岳林,袁翔.汽油机燃烧过程的数值模拟[J].长沙交通学院学报, 1999,9:19-23.
[94]沈建平.内燃机缸内流场数值模拟研究现状及发展[J].车用发动机, 1997(l):11-15.
[95]蒋炎坤,陈小东,陈国华.基于流场动力学特性的发动机稳流数值试验研究[J].机械工程学报, 2004,40(9):129-132,137.
[96]沈建平,吴承雄.内燃机缸内湍流运动数值模拟研究[J].内燃机学报, 1997(4):338-404.
[97]蒋炎坤. CFD辅助发动机工程的理论与应用[M].科学出版社, 2004. 263-264
[98]李隆键,余涛,张小燕,汪正胜.四气门发动机进气流动特性的数值建模[J].热科学与技术, 2004,3(3):242-245.
[99]刘书亮,孙晓燕等.四气门汽油机中滚流运动的三维数值模拟[J].工程热物理学报, 1999(l):116-120.
[100] Heywood J B著,唐开元等译.内燃机原理[M].武汉海军工程学院,1992.
[101]李云清,刘宾,王会霞.基于AVL-FIRE的汽油机缸内滚流的模拟计算[J].柴油机设计与制造, 2007,15 (3):118-121.
[102]蒋炎坤,陈小东,陈国华.化油器-进气管-缸内系统三维数值模拟研究[J].武汉理工大气学学报, 1998,26(11):98-100.
[103]刘德新,李丹,冯洪庆,于吉超.四气门汽油机进气道气流运动的三维数值模拟研究[J].内燃机工程, 2006,4:36-38.
[104] AVL List Gmbh. Fire使用手册[M].上海: AVL公司, 2008.
[105] AVL List Gmbh. Advanced Use of CFD Tools for High Performance Engine Simulations. AVL公司2005用户论文集.
[106] AVL Fire vs CFD Combustion[M].上海: AVL公司, 2008.
[107] AVL Fire vs CFD user Guide[M].上海: AVL公司, 2008.
[108] S.V.Patanker. Numerical Heat Transfer and Fluid Flow. Hemisphere, Washington,1980.
[109]李玉锋,刘书亮等.提高四气门汽油机缸内滚流强度的研究[J].内燃机学报, 1999(3): 22-26.
[110] P.K.Senecal,J.Xin,andR.D.Reitz.Predictions of Residual Gas Fraction in IC Engines[C]. SAE 962052.
[111]祖炳锋,康秀玲,付光琦,徐玉梁,刘捷.车用四气门汽油机气道及缸内流场的瞬态模拟[J].天津大学学报, 2005,1:12-18.
[112] R D. Reitz. Progress in Diesel Engine Intake Flow Field and Combustion Modeling[J]. SAE, 1993:1624-1633.
[113]杨迪,顾宏中.火花点火发动机燃烧过程的多维模拟[J].车用发动机, 1999,2:1-4.
[114] ZhichaoTan, RolfD.Reitz. An ignition and combustion model based on the level-set method for spark ignition engine Multi-dimensional modeling[J]. Combustion and Flame, 145(2006):l-15.
[115] Rogers D. Engine combustion analysis-Current and future developments[J]. Engineering Technology, 2005,8,5: 39-42.
[116] Rogers D. Introducing engine combustion pressure sensor technology[J]. Engineering Technology, 2006, 9(2): 45-49.
[117]孙晶晶.汽油机进气及燃烧过程数值模拟研究[D].北京:北京交通大学, 2006.
[118]黎苏,懂正身,张旭等.汽油机非稳定工况燃烧放热率计算模型的修正[J].内燃机学报,2000,18(3):275-278.
[119]宫春峰,刁增祥,彭莫.内燃机的动力特性[J].内燃机学报, 2000,18(4): 439-442.