截割参数对镐型截齿截割比能耗的影响

为了研究相关截割参数对截割比能耗的影响，基于直线截割试验装置，在不同截割角条件下，使用5种不同锥角的镐形截齿对一种砂岩进行截割试验，研究了相关角度参数对截割力和比能耗的影响；在截割角为55°时，使用锥角80°的截齿，在不同截割厚度和截线距条件下进行截割试验，探讨了截割厚度和截线距对截割力和截割比能耗的影响。试验结果表明，清理角对截割力和截割比能耗有显著的影响，当清理角过小时，截齿与岩石之间产生严重的摩擦使截割力明显较大，从而使截割比能耗较大。当清理角小于等于10°时，平均截割力随截齿锥角的增大呈线性增大，随前角的增大呈线性减小，此时截割比能耗明显小于清理角大于10°时的截割比能耗，但锥角和前角对截割比能耗未见明显的影响趋势。平均截割力随截割厚度和截线距的增大呈线性增大。截割比能耗随截割厚度的增大呈幂函数减小。截线距与截割厚度的比值存在一个最优值使截割比能耗最小，此时截割比能耗相对无截槽影响时约降低65.1%。截线距与截割厚度比值的最优值为2或3，且该比值不受截割厚度和截线距的影响。这些结论对镐型截齿工作角度的设计及采掘机械工作机构截齿布置有重要的指导意义。

Effects of cutting parameters affecting on specific cutting energy of conical picks

In order to investigate the effects of relevant cutting parameters on specific energy,rock cutting tests were carried out using five conical picks with different cone angles on a sandstone under different levels of attack angles based on the linear rock cutting machine.The effects of relevant angles on cutting force and specific cutting energy were studied in detail.Some rock cutting tests were also carried out under different levels of depth of cut and line spacings with the attack angle of 55° using the conical pick with the cone angle of 55°.The effects of depth of cut and line spacing on cutting force and specific cutting energy were discussed in detail.Experimental results indicate that there is a significant influence of clearance angle on cutting force and specific cutting energy.If the clearance angle is too small,serious friction between the pick and rock would dramatically increase mean cutting force and further increase specific cutting energy.When the clearance angle is greater than 10°,mean cutting force linearly increases with the increasing cone angle of conical pick,and linearly decreases with the increasing rake angle.In this condition,the specific cutting energy is significantly smaller comparing with that under the clearance angle smaller than 10°.However,there is no obvious influence of rake angle and cone angle of the pick on specific cutting energy.The mean cutting force linearly increases with the increasing depth of cut and line spacing.The specific cutting energy increases with the increasing depth of cut with power function,and there is an optimum value of the ratio of line spacing to depth of cut to obtain the minimum value of specific cutting energy.The specific cutting energy under optimum relieved cutting approximately decreases by 65.1% comparing with that in unrelieved cutting mode.The optimum value of the ratio of line spacing to depth of cut is 2 or 3,and it is not affected by the depth of cut and line spacing.All conclusions of this study have an important guiding significance for designing the work angles of conical picks and picks arrangement on work units of mining machinery.