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 spac- ings 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 in- creasing 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 lin- early increases with the increasing depth of cut and line spacing. The specific cutting energy increases with the in- creasing 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 ap- proximately 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.