局部接触对制动盘温度及摩擦性能的影响

Effect of Local Contact on Temperature of Brake Disc and Friction Performance

将摩擦块设计为2侧接触和中间接触2种接触形式,利用轨道列车缩比惯性制动试验台,分别在制动压力为0.50,0.75和1.00 MPa,制动速度为50,80,120,160和200 km·h-1条件下,研究局部接触形式对制动盘表面温度和摩擦性能的影响,并与全接触形式对比。结果表明:局部接触的位置对盘面温度和摩擦系数的影响明显;在制动速度为200 km·h-1、制动压力为1.00 MPa工况下,局部接触导致摩擦系数降低约10%左右;相对于全接触,中间接触时盘面峰值温度升高约31%、最大温差增大约37%,2侧接触时盘面峰值温度下降约11%、最大温差减小约68%。其原因在于中间接触时接触区域与盘面高能量区重合,起到了加剧温度集中程度的作用,而2侧接触时接触区域偏离高能量区,有助于改善盘面温度的均匀性。

The bilateral contact and middle contact patterns were designed for the friction blocks. The effects of local contact patterns on the surface temperature of the brake disc and friction performance were studied on the reduced-scale inertia braking test bench of track and train under the braking pressures of 0. 50, 0. 75 and 1. 00 MPa at the braking speeds of 50, 80, 120, 160 and 200 km·h-1 respectively, and were compared with those of full contact pattern. Results show that the position of local contact has an obvious effect on the surface temperature of the disc and friction coefficient. At the speed of 200 km·h-1 and the braking pressure of 1. 00 MPa, the friction coefficient is reduced by about 10% due to local contact. Compared with the full contact, the peak temperature of disc surface rises by 31%, and the maximum temperature difference is increased by 37%for the case of middle contact, while the peak temperature decreases by 11% and the maximum temperature difference decreases by 68% under bilateral contact. The reason is that the contact area coincides with the high energy area of the disc surface during the middle contact, which intensifies the temperature concentration degree, while the contact area deviates from the high energy area during the bilateral contact, which helps to improve the temperature uniformity of disc surface.