制动过程中闸片材料与制动盘温度关系试验研究

Experimental Study on the Relationship Between Brake Pad Material and Brake Disc Temperature During Braking

为探讨碳/陶制动盘与不同闸片材料的匹配性,对碳/陶制动盘分别与碳/陶复合闸片、铜基粉末冶金闸片和铁基粉末冶金闸片组成的摩擦副进行制动试验,研究了在制动过程中盘面各点瞬时温度、最高温度、闸片温度与制动工况的关系。结果表明:碳/陶制动盘与碳/陶复合闸片摩擦副温度及温度梯度均高于其他2种摩擦副,其温度梯度在低速制动时随压力的增加而明显增加,当制动速度较高时,温度梯度并没有随压力的增加而增加;对于碳/陶制动盘与铜基和铁基粉末冶金闸片摩擦副,随制动速度和压力的提高,盘面温度梯度变化不明显。原因在于材料导热性和起始摩擦因数决定了盘面的散热能力和制动功率,碳/陶制动盘与碳/陶复合闸片摩擦副因较高的起始摩擦因数以及较低的导热性,其制动功率高和散热能力低,导致盘面温度持续升高。

To discuss the matching between carbon/ceramic brake disc and different brake pad materials,the braking test was conducted on the friction pairs consisting of carbon/ceramic brake disc and carbon/ceramic composite brake pad,copper-based powder metallurgy brake pad and iron-based powder metallurgy brake pad.The relationship between the instantaneous temperature and the maximum temperature on the brake disc surface,the brake pad temperature and the braking condition was studied.The results show that the temperature and temperature gradient of the friction pair of carbon/ceramic brake disc and carbon/ceramic brake disc brake pad are higher than those of the other two kinds of friction pairs,and the temperature gradient of carbon/ceramic brake disc increases obviously with the increase of pressure at low speed,but does not increase with the increase of pressure at high speed.For the friction pairs between carbon/ceramic brake disc and copper and iron-based powder metallurgy brake pads,the temperature gradient of disc surface has no obvious change with the increase of braking speed and pressure.The reason is that the thermal conductivity and initial friction coefficient of the material determine the heat dissipation capacity and braking power of the disc surface.The friction pair of carbon/ceramic brake disc and carbon/ceramic brake pad has high initial friction coefficient and lower thermal conductivity,so its braking power is high and heat dissipation capacity is low,resulting in the continuous rise of the disk surface temperature.