| Coal is an indispensable energy source for China’s development,and coal mining cannot be separated from roadway excavation,which is a pioneering project in coal mining.With the continuous improvement of underground equipment and mining technology in coal mines,the cross-sectional size of roadway is constantly increasing.However,due to the limitations of the cutting area of the current mainstream cantilever roadheader machine,secondary cutting is often required to shape large cross-section roadway.Therefore,it is necessary to conduct research on the secondary cutting technology of cantilever roadheader machines for large cross-section roadway.In addition,the working environment underground is harsh,and the flying coal dust during cutting blocks the driver’s line of sight,making the cutting efficiency and cutting shaping effect of the roadway unsatisfactory.This not only exacerbates the imbalance between mining speed and excavation speed,but also fails to fully ensure the personal health and construction safety of workers during excavation.The automatic cutting technology of cantilever roadheader machine can help solve these problems.On the basis of summarizing and analyzing the cutting technology and theoretical research status of domestic cantilever roadheader abroad,this thesis conducts research on the automatic cutting and molding method of large cross-section coal roadway cantilever roadheader,which plays an important role in improving the efficiency of tunnel excavation,alleviating the imbalance in excavation and ensuring excavation safety.The main research results of this article are as follows:(1)Based on the analysis of the main working mechanism of the roadheader,a simplified model of the roadheader and a spatial posture coordinate system are established.The kinematics of the roadheader is analyzed using the principle of robot kinematics and homogeneous transformation of the coordinate system.The posture expression of the cutting head in the roadway coordinate system is derived,and the relationship between the hydraulic cylinder piston stroke and joint variables is obtained,laying a theoretical foundation for the cutting path control of the roadheader;(2)A simulation was conducted using Matlab on the ultimate cutting area of a cantilever and the cutting effect of the roadway section under different body posture parameters.The simulation results showed that secondary cutting can meet the cutting requirements of large cross-section coal tunnels,verifying the correctness of the secondary cutting theory;In addition,the posture parameters of the machine body have a significant impact on the cutting forming effect,and the stability of the tunneling machine body should be maintained during the cutting process.(3)According to the geological conditions and reports of Wangjialing Mine,a roadway tunneling model is established using FLAC 3D software to simulate the deformation of roadway surrounding rock under different cutting paths,and a reasonable secondary roadway cutting path is determined based on the actual situation in the mine;(4)A simplified model of the cutting head is established,and the coordinates of the inflection point of the cutting path are determined based on the relationship between the cutting head and the roadway boundary when the roadheader is cutting.Based on the determined inflection point coordinates and the planned cutting path,a cutting path control program is compiled,and the simulation of the cutting path control process is conducted using Matlab software,verifying the effectiveness of the cutting path control theory;(5)Relying on the intelligent supporting equipment and system of the 12307 intelligent chemical working face in Wangjialing Mine,an underground industrial test is conducted in the belt roadway.The test results show that the system can operate smoothly during the cutting process of the roadheader,and the section is relatively flat after the roadway is cut and formed.The thesis has 48 figures,9 tables and 89 references. |
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