特大型电动轮矿用自卸车联合制动特性研究

Research of blended braking characteristics of super-big electric wheels of mining dump truck

为了研究特大型电动轮矿用自卸车下坡联合制动时的制动特性,分析联合制动时电阻栅能耗制动及液压多片湿盘式制动器制动功率的分配,以湘电重装满载整车重量达520 t的自卸车为研究对象,建立了自卸车电阻栅能耗制动及液压多片湿盘式制动器联合制动系统动力学模型,利用Mtlab/simulink对该自卸车在不同下坡坡道上的紧急联合制动进行了数值分析计算,获得制动特性曲线。结果表明:初速度为30 km/h时,在不高于10%的坡度下紧急制动距离不超过21 m;平均比制动力在不同坡道基本保持不变,最高值为0.35左右;后轮比制动力大于前轮比制动力,侧滑、跑偏的可能性大于转向失控的可能性;当满载重心向后轴移动时,平均比制动力保持不变,前后轮比制动力差距减小,可有效利用地面粘着力;电阻栅能耗制动与液压多片湿盘式制动器的平均制动功率之比约为2∶3。研究表明该联合制动系统可有效减轻主制动器负荷,提高制动效能,延长主制动器使用寿命。

In order to obtain the blended braking characteristics of super-big electric wheels of mining dump truck on different downhill slope,and analyze the power distribution between grid resistance electric dynamic brake and hydraulic wet multi-disc brake,the dynamic model of blended braking system was established by using a certain type of 520 tons gross vehicle weight dump truck as research object.Results show that with the initial velocity of 30 km/h,emergency braking distance is less than 21 m on different slopes below 10%;the average specific brake force nearly remain unchanged on different slope,and the maximum value is about 0.35;for rear specific brake force is bigger than that of front,the possibility of sideslip and deviation is bigger than that of out of steering control;the specific brake force difference between rear and front can be reduced by moving the center of gravity to the rear axle,while the average specific brake force remain unchanged,so the ground adhesion can used effectively;the brake power ratio between grid resistance and wet multi-disc brake is about 2∶ 3.These results shows that the blended braking system can reduce the brakes load effectively,increase braking performance,and extend the service life of the main brakes.