Cutting mechanical study of pick cutting coal seams with coal and rock interface

Shearer is an indispensable and important equipment for coal mining and the mining efficiency of shearer depends on the performance of pick to a great extent. In this paper, we conducted a series experiments of single pick cutting on the coal and rock cutting testbed. Simultaneously, we built the single pick cutting coal seam model, based on which, considering the strength condition of coal seam and coal–rock interface, the rotary cutting mechanical model of pick cutting coal seam with coal–rock interface is established. According to the crushing theory of coal and rock interface, this paper analyzed stress strain and strength condition of the area surround the interface, which ensured the basics for the further research. The data of picking force in the cutting process under different experimental conditions was collected by the sensor installed on the drum, a phenomenon appeared in the amplitude domain analysis of the data that the bigger force arising along with the greater compressive strength difference between coal seam and coal–rock interface, which means the force is positively correlated with the compressive strength. The results of time domain analysis shown that some basic properties of the cutting load changes over times.