【作者】 张兰春；

【导师】 常思勤；

【作者基本信息】 南京理工大学 ， 车辆工程， 2009， 博士

【摘要】 本文以适用于发动机前置前驱经济型轿车的功率分流式无级变速器(Power SplitContinuously Variable Transmission,PSCVT)作为研究对象。按照先整体,后部件的研究思路,首先对该变速器的整体方案进行了设计并通过性能仿真验证了其结构及性能参数设计的合理性和正确性;然后运用理论与试验相结合的方法对PSCVT的核心部件——带式无级变速单元的调节方式、力学分析及速比控制进行了深入研究。主要内容包括以下几个方面:1.PSCVT总体方案设计与参数优化。针对应用对象的结构布置特点,在运动学及力学分析的基础上,完成了PSCVT总体方案设计;运用优化理论方法对变速器主要性能参数及各主要零部件的结构参数进行了优化设计;应用虚拟样机技术完成了PSCVT各部件的三维建模和整个变速器的总体装配及箱体结构的设计。2.PSCVT的性能仿真研究。为了评价PSCVT本身及其与整车匹配性能,通过对汽车性能仿真软件Advisor的二次开发,搭建了针对PSCVT性能评价的整车动力及经济性能仿真平台;对设计的变速器进行数学建模,并针对所选车型在该仿真平台上进行了仿真计算。3.无级变速单元全电调节方式的提出与设计实现。无级变速单元作为PSCVT的核心部件,其性能决定着整个变速器的性能。在分析对比现有无级变速器调节方式优、缺点的基础上,提出了一种采用双电机分别调节无级变速单元主、从动带轮工作半径以实现速比精确调节的全电调节新方案并对该方案进行了工程化设计和原理样机研制。4.全电调节无级变速单元传动过程中的力学分析。为了给无级变速单元的夹紧力控制、速比执行机构的设计及执行电机的选型和控制提供理论依据,对其传动过程中的受力进行了分析,根据得到的无级变速单元力学模型并结合功率分流式无级变速器中无级变速单元的工作特性,通过仿真计算得到了其主、从动带轮动盘夹紧力与传递转矩的关系以及两者随速比变化的规律。5.PSCVT速比控制研究。通过对无级变速单元速比变化率以及整车动力学的建模和仿真计算,得到了速比变化率对整车性能的影响关系;从提高汽车性能的目的出发,制定了合理的速比控制策略,并对基于角位移改变无级变速单元速比的执行电机控制进行了研究,设计了模糊滑模变结构控制器。6.全电调节无级变速单元的试验研究。对无级变速单元全电调节方案进行了工程化设计和原理样机研制,设计了针对全电调节无级变速单元性能测试的试验台架,对该方案的可行性进行了试验验证。试验内容包括无级变速单元速比与执行电机转角关系测试、无级变速单元传递效率随不同夹紧力位置的变化规律、其转矩和转速损失随负载转矩的变化规律、无级变速单元的转矩传递容量等稳态测试以及通过控制执行电机转角对制定的特定目标速比进行跟踪调节的可行性验证。更多还原

【Abstract】 A power split continuously variable transmission (PSCVT) with two-stage step-up gearbox concept in the context of the mini car with engine of FF application was presented in this dissertation. The scheme of PSCVT was designed and verified by simulation. The continuously variable unit(CVU), as the key part of PSCVT was researched deeply by means of combination of simulation calculation and prototyping test. The research was performed as follows:1. PSCVT scheme design. Firstly, the whole scheme of PSCVT was studied and analysised based on the kinematics and mechanics according to the configuration characteristic of the application objection; Secondly, the main PSCVT performance parameters were optimized and confirmed by means of mechanical optimization methodology. Finally, the three-dimension modeling and assembly of the whole gearbox were done and the gearbox configuration was optimized by dint of virtual prototype technology.2. PSCVT performance simulation research. PSCVT mathematic model was established and embedded into the simulation software Advanced Vehicle Simulator (ADVISOR) to finish the whole vehicle modeling with the purpose of estimating the performance PSCVT itself and matching between PSCVT and the whole vehicle. The simulation was carried out according to the chosen vehicle under different driving cycles.3. Electromechanical CVU pulley actuation scheme research and design. As the key part of PSCVT, CVU plays an important role to the whole transmiison performance. An electromechanical CVT pulley actuation system for the variable pulley set (variator) was presented based on the analysis on the other actuation systems for speed ratio control of CVT, and the engineering design as well as prototype manufacture were finished.4. Electromechanical pulley actuation CVU force analysis. The force working on CVU was analyzed and force model was obtained with the purpose of buildbing up theory foundation for the CVU design, the choice as well as the control of actuation motors used for speed ratio shifting and clamping control. The relationship between the pulley clamping force with the torque transmitted by CVU was verified under different speed ratios and the influence that the shape of the instantaneous belt configuration playing to the pulley clamping force was obtained by simulation and calculation to the force model based on the transmission characteristics of PSCVT.5. PSCVT ratio control research. The influence that speed ratio changing rate playing to the vechle performance was obtained by modeling and simulation calculation to the vechile dynamics. To improve the vehicle performance, the ratio control strategy was established and sliding mode variable structure fuzzy controller for the angle displacement of motor which was used to changing the speed ratio of CVU was designed.6. Experiment research on electromechanical pulley actuation CVU. The test rig was established for the electromechanical pulley actuation CVU prototype performance test and the experiment study was done to verify the feasibility of the scheme.The test was comprised of stable test and dynamic test. The former contained the test on relationship between the CVU speed ratio and the motor angle, the law between the CVU transmission efficiency and clamping force, the law between the torque loss as well as the speed loss and the load respectively and the transmission capability of CVU, and the latter was the test on the CVU speed ratio control from initialization to the goal by controlling the motor angle.更多还原