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在汽车盘式制动系统中,因各种原因如热膨胀和制动盘尺寸的不精确等,导致摩擦热无规则分配,这就是大家熟知的因摩擦热产生的热弹性变形影响摩擦接触压力分配,并导致热弹性不稳定性(TEI)。在制动盘表面上摩擦接触压力集中作用在一个或几个小区域内,于是这些区域达到很高的温度,我们称之为热点。热点与摩擦块作用产生低频振动,我们称之为制动颤振(Judder),即大家所熟悉的制动发抖现象。制动盘厚度差异(DTV)将进一步促使摩擦局部接触,制动盘侧向摆差(LRO)也可导致无规则的摩擦接触。本文研究了各种摩擦接触状态对热模型的影响,应用红外线照相技术和振动测量分析了盘式制动系统制动颤振特性。应用热弹性不稳定性理论改变研究中所用的原始的摩擦材料,并用动力测功机进行试验验证,证明了改变后的摩擦材料有更好的抗制动颤振性能。
In the automobile disc brake system, the frictional heat distribution is irregular due to various reasons such as thermal expansion and the inaccuracy of the size of the brake disc, which is well-known that the thermal elastic deformation caused by frictional heat affects the frictional contact pressure distribution , And lead to thermo-elastic instability (TEI). Frictional contact pressure on the surface of the brake disc concentrates in one or several small areas, so these areas reach very high temperatures, which we call hot spots. The hot spot and the friction block produce low-frequency vibration, which we call the Judder, which is known as the brake shaking phenomenon. Difference in brake disk thickness (DTV) will further promote frictional local contact, and brake rotor lateral slip (LRO) may also result in random frictional contact. In this paper, the effects of various frictional contact states on the thermal model are investigated. The characteristics of the brake flutter of the disc brake system are analyzed by infrared photography and vibration measurement. Using the theory of thermoelastic instability, the original friction material used in the study was changed, and the dynamic friction dynamometer was used to verify the experimental results. It is proved that the modified friction material has better anti-flutter performance.