Analysis Of Cutting Characteristics And Load Chaos Of Cuttinghead In Roadheader

Based on the present research status of cutting and cutting characteristics,this paper systematically analyzes the theory of the broken coal rock,the development and application of coal and rock cutting test benches at home and abroad,and aims at the structural features and cutting teeth of the existing coal rock cutting test bench.The forms of movement,cutting characteristics and related research results are reviewed to analyze the deficiencies and areas for improvement.The theoretical analysis,experimental measurement and numerical simulation were used to conduct in-depth research on the mechanism of broken coal(rock),simulated cutting test of cutting head,characteristics prediction of boring machine and system dynamics of cutting head.According to the coal(rock)cutting theory combined with various experimental phenomena in the experiment,the mechanism of rotary coal broken rock(rock)with a pick-shaped pick was discussed.Using finite element software LS-DYNA,according to the test condition parameters,the performances of the cutting characteristics of the cutting head under different cutting geometry parameters,pick spacing and cutting thicknesswere analyzed;the results were compared with the cutting theory and cutting experiment.Knowing that the simulated cutting results can reflect the actual cutting conditions to a certain extent,and provide a theoretical basis for the study of the cutting characteristics and corresponding parameters of the roadheader.In order to study the real working conditions when the cutting head cuts coal rock,based on the similarity theory,based on the theory of cutting coal(rock)theory of the roadheader,the properties of coal(rock),cutting head,cutting teeth and cutting load are established.Based on similar criteria,a coal(rock)cutting test bench was developed.Invented a rotating shaft axial force measuring device(ZL 201610123719.3).The device solves the problem of load testing in the rotary cutting test of the cutting head of a roadheader,and provides effective research for the study of the cutting characteristics of the cutting head(which can also be extended to other rotary cutting mechanisms,such as shearer rollers,etc.).Test Platform.Based on the existing cutting force prediction formula,a new prediction model of the cutting performance of the roadheader is proposed.The reliability of the model is verified by obtaining experimental data and existing empirical formulas.The dynamic model of the cutting head of the roadheader was established.Based on the chaos theory,the dynamic characteristics of the coal(rock)system of the cutting head were explored,and the external performance of the load with uncertainty was considered as a deterministic power.The chaotic phenomenon of the system reveals the intrinsic essential laws inherent in the external phenomena such as irregularity,uncertainty,and aperiodic cutting load of the cutting head.