驱动轮外层材料对桉树修枝机攀爬性能影响的试验测试

Experimental Test on Effect of the Outer Layer Materials of Driving Wheels on the Climbing Performance of Eucalyptus Pruning Equipment

为探明修枝机驱动轮外层材料与桉树树皮之间的摩擦机理,以选出具有较大摩擦力的驱动轮外层材料,采用试错法对驱动轮粘贴或者安装具有不同硬度和层厚的材料开展修枝机的攀爬性能测试,结合桉树树皮表层的结构特征,对驱动轮外层材料与桉树树皮的接触情况和摩擦机理进行分析。结果表明,除外层为聚氨酯裹层和薄层胶带的驱动轮存在打滑且不能顺利攀爬树干外,具有其余外层的驱动轮均能顺利攀爬树干且以外层为厚层橡胶裹层的驱动轮攀爬性能最优。较软的驱动轮外层材料容易变形,不仅在宏观尺度上与桉树树皮有较大面积的接触,而且在微观尺度上也有较为紧密的接触。较大的面积和紧密的接触可以减少桉树树皮微凸体的剪切应力,避免微凸体被破坏,获得较大的摩擦力,从而使修枝机的爬树修枝部分具有更大的攀升力。驱动轮外层应选用硬度较小而且层厚较大的材料。驱动轮外层材料的最佳硬度值,建议以45HA作为硬度上限来对驱动轮的材料进行选取。另外,驱动轮外层额外增加较大的防滑条纹并不能增加驱动轮与树干之间的摩擦力,不推荐在驱动轮外层额外增加较大的防滑条纹。

In order to explore the friction principle between the outer layer material of the driving wheel of the pruner and the eucalyptus bark to select the outer layer material of the driving wheel with greater friction,a trial and error method was used to paste or install materials with different hardness and layer thickness on the driving wheel to carry out the climbing performance test of the pruning machine.Coupled with the structural characteristics of the eucalyptus bark surface,the contact between the outer material of the driving wheel and eucalyptus bark and the friction mechanism were analyzed.The results show that,except for the driving wheels with the outer layer of polyurethane coating and thin layer of tape that slipped and were unable to climb the trunk smoothly,the driving wheels with the remaining outer layers could climb the trunk smoothly and the driving wheels with thick rubber as the outer layer had the optimal climbing performance.Soft driving wheel outer material was easy to deform.It not only had larger-area contact with the eucalyptus bark on the macro scale,but also had a closer contact on the micro scale.A large-area and close contact could reduce shear stress of the eucalyptus bark micro-protrusions,prevent the micro-protrusions from being damaged and obtain greater friction,so that the climbing and pruning part of the pruning machine could have a greater climbing force.The outer layer of the drive wheel should be made of a material with a lower hardness and a larger layer thickness.For the best hardness value of the outer material of the driving wheel,it is recommended to use 45HA as the upper limit of the hardness to select the material of the driving wheel.In addition,adding larger anti-skid stripes on the outer layer of the drive wheel can not increase the friction between the drive wheel and the trunk.It is not recommended to add larger anti-skid stripes on the outer layer of the drive wheel.