干式离合器温度模型研究

Clutch control for automatic transmission is the commen pivotal central technology . Ensuring the consistency of clutch control effect , meanwhile extending the service life is a difficulty for clutch control technology. The important reason is the temperature field information that directly affect the torque transmission characteristic of clutch , due to high-speed rotation, difficult to obtain. Simultaneously, clutch transmitted torque, friction coefficient, pressing force, and clutch temperature field are strong-coupling and nonlinear. This project treats dry clutch as the object of study. With the establishment of clutch thermosetting coupling dynamics model that has temperature variable quantity, study the influencing regulation of temperature parameters towards clutch sliding friction properties. For the sake of clutch torque dynamic estimation establish theoretical foundation. On this basis, calculate the slipping power by clutch torque and sliding speed difference. According to thermodynamics and heat transfer theory, combined with charactetistics and structure of clutch, establish three-dimensional unsteady heat balance equation. And using finite element method analysis the offlined temperature field. Then study low dimensional homeomorphism mapping of the high dimensional model. Build the clutch temperature model that satisfy real-time demand, and master clutch temperature changing rule. Basing on knowledge model method build the relational knowledge base of clutch transmitted torque, friction coefficient, sliding speed difference, pressing force and temperature field. Realization the thermosetting coupling system decouple, and check the temperature model.

离合器控制是自动变速技术的共性关键核心技术，如何保证离合器控制效果一致性的同时延长其使用寿命是离合器控制技术的难点，其重要原因是直接影响离合器扭矩传递特性的温度场信息由于离合器的高速旋转而难以获取，同时离合器传递的扭矩、摩擦系数、压紧力与离合器温度场强耦合且非线性。本项目以干式离合器为研究对象，建立热固耦合离合器滑磨动力学模型，研究温度参数对离合器滑磨特性的影响规律，为离合器扭矩动态估计奠定理论基础；在此基础上，根据离合器扭矩和滑转速差计算滑转功率，基于傅立叶导热定律和能量守恒定律，建立离合器三维非稳态热平衡方程，并利用有限元方法进行离线温度场分析，进而进行高维模型的低维同胚映射研究，建立满足实时控制需求的离合器温度模型，掌握离合器温度变化规律；基于知识模型的方法建立离合器滑磨特性关系知识库，进而基于数据驱动的方法实现热固耦合系统解耦，并通过得到的知识库对温度模型进行完善和验证。

干式离合器转矩是直接影响离合器控制精度的关键因素。离合器温度是影响干式离合器摩擦转矩的关键参数。本项目通过有限元方法搭建了干式离合器在线温度模型。由于摩擦系数对离合器温度和转矩都有很大的影响，项目中通过自主设计的多参数摩擦系数台架对干式离合器的摩擦系数进行了详细的分析并搭建了多参数摩擦系数模型。对于干式离合器摩擦转矩而言，压紧力也是一个重要因素。而摩擦片温度和磨损对压紧力会产生较大影响，因此项目中对膜片弹簧的负载特性进行了研究并搭建了离合器压紧力模型以消除摩擦片温度和磨损的影响。最后项目对所有模型进行了整理，并搭建了干式离合器摩擦转矩计算模型。该模型可以较为精确地计算出干式离合器的摩擦转矩。