高速列车制动片摩擦块尺寸对制动噪声特性的影响

Effect of Friction Block Size of High-speed Train Brakes on Noise Characteristics

同一工况下,在制动摩擦噪声试验机上使用3种不同尺寸的圆形摩擦块进行制动摩擦噪声对比试验,通过对不同摩擦块尺寸状态下的界面噪声信号进行等效声压级分析和频谱分析,研究摩擦块尺寸对制动噪声特性的影响;对界面磨损形貌采用光学显微镜和二维轮廓仪进行分析,并计算出摩擦界面上的摩擦弧长,以揭示摩擦块尺寸对制动噪声行为的影响机制。结果表明:在试验条件下,摩擦面积相同时,大圆形摩擦块能有效地抑制制动噪声,而中圆形和小圆形摩擦块的制动噪声强度较大;相较于大圆形摩擦块,中圆形和小圆形摩擦块表面出现明显犁沟和剥落等“不平顺”磨损因素会造成高强度的尖叫噪声;大圆形摩擦块相比于中圆形和小圆形摩擦块的摩擦弧长较短,这也是造成大圆形摩擦块状态下制动噪声强度减弱的一个重要因素。

Under the same testing condition,circular friction blocks with three different sizes of train disc brakes were used to carry out comparative experimental study of frictional noise on brake dynamometer.Equivalent sound pressure level analysis and frequency domain analysis of these noise signals were performed,to study the influence of friction block size on brake noise characteristics.The interface morphology was analyzed by using optical microscope and two-dimensional profiler after the experiment,and the length of friction arc on the friction interface was calculated,to reveal the influence mechanism of friction block size on brake noise behavior.The results show that,under a certain test condition and when the total apparent contact areas are made to be identical,the large circular block can effectively contain the brake noise,while frictional noise generated by two intermediate circular blocks or three small circular blocks exhibit high intensity.Compared with large circular block,on the surface of intermediate and small circular blocks there exist irregular wear features such as obvious ploughing and detachment,these characteristics lead to high intensity brake noise.The frictional arcs of large circular block are much shorter than those of intermediate and small circular blocks,this is also an important factor causing the reduction of brake noise intensity of large circular block.