针对汽车安全玻璃热弯成形的高温摩擦试验机研制与试验

Development and Test of High Temperature Friction Tester for Hot Bending of Automotivesafety Glass

针对汽车安全玻璃热弯成形过程中的摩擦行为,基于库伦摩擦定律设计测量不同温度状态下汽车安全玻璃与模具之间摩擦系数的高温摩擦试验机,并进行了性能验证。该摩擦试验机由高温加热装置、数据采集与处理系统、控制系统和机械加载装置等组成,并利用ANSYS Workbench有限元分析软件对关键结构部件的刚度和强度进行仿真校核。在机械加载装置施加载荷后,试验机通过贴在摩擦头上的应变片将摩擦力引起的弯曲应变转换为电信号,利用数据采集与处理系统将采集到的电信号进行处理与存储。利用该试验机对汽车安全玻璃在不同温度条件下与模具之间的摩擦行为进行研究。结果表明,摩擦系数随着成形温度的升高整体呈现增大趋势。当加热温度接近玻璃化转变温度时,玻璃接近高弹态区域,温度对摩擦系数的影响减小,增幅减小。试验机检测性能稳定,满足用于研究实际生产中汽车安全玻璃热弯成形摩擦问题的需求。

To better understand the friction behavior of automotive safety glass during the hot bending forming process,a high temperature friction tester,based on the Coulombs law of friction,was designed and built to measure the friction coefficient between the automotive safety glass and the mould at different temperature levels,and validation tests were conducted.The tester is composed of high-temperature heating equipment,data acquisition and processing system,control system and mechanical loading equipment.The rigidity and strength of the key component are simulated and verified using finite element analysis software ANSYS Workbench.Under the applied load by mechanical loading device,the strain gauge placed on the friction head converts the friction-induced bending strain into electrical signals.Then,the collected electrical signals are processed and stored by the data acquisition and processing system.At last,the friction tests of automotive safety glass with the mould were carried out at different temperature levels.The results show that the friction coefficient increases with increasing forming temperature.When the forming temperature is close to the glass transition temperature,the mechanical state of the glass is close to High elastic state.In this case,the amplitude of friction coefficient is reduced due to the fact that the effect of forming temperature on the friction coefficient decreases.Furthermore,the performance of the tester is stable and suitable to carry out the friction behavior tests of the automobile safety glass during hot bending forming process.