Study On Dynamic Characters Simulation For Work Mechanism Of Coal Cutter Based On Pulsating Flow Hydraulic Impact System

In this thesis, the research analyzes the dynamic parameters that affect thedynamic performance of the pulsating flow hydraulic impact system, and studieswork parameters and structure parameters on the influence of the impact systemthrough the numerical simulation of coal impact crushing. The pulsating flowhydraulic impact system is proposed on the mechanism of impacting coal and itis the key impacting device of the impact-mining machine.This thesis firstly introduces the engineering background of the research,and then elaborates the dynamics progress of the coal and rock crushing theoryand impact dynamics as a whole. After fully grasping the power bond graphmodeling rules and analyzing the working process of the hydraulic impactsystem according to the principle of alternating-flow hydraulic technology, thepower bond graph is establishes and the impact system mathematical model isdeduced. In addition, this paper converts the impact mechanism to the impactmechanical system from the perspective of impact dynamics, and establishes itswave mechanics equivalent model. The thesis studies the interaction processwhile impacting the coal and rock, and observes the stress wave change law,energy conversion process and impacting efficiency. The result we obtainedprovides the boundary conditions for the simulation of the pulsating flowhydraulic impact system. After established mathematical model of the pulsating flow hydraulicimpact system, the research designs a3factors and5levels orthogonalexperiment table of2-target to finds out the factors that are relatively sensitive tothe dynamic characteristics of the system and improve the research efficiency bytargeted simulation. According to the established mathematical model, the thesisstudies key parameters of dynamic impact system combined ANSYS/LS-DYNAand MATLAB/Simulink. The simulation obtains the impact system pressure, thelaw of flow rate, the impact head displacement and speed curve, and the loadchanges in the process of crushing the coal.In the process of studies for system performance parameters, the thesis callsSimulink models and builds a simulation platform of the pulsating flowhydraulic impact system using MATLAB GUI (Graphics User Interface)technology module. Coupling of the structural parameters and workingparameters, the simulation platform can plot a series of key curve on impactsystem, which is significant to study the dynamic characteristic of the system.The purpose of the research is to study the dynamic characteristics of theimpact system with methods of building dynamic equation and equivalent wavemechanics model. With the help of computer simulation, we find an efficientpath to study the pulsating flow hydraulic impact system. In addition, theresearch offers theoretical basis and reference significance for the design of theimpact-mining machine of the work mechanism.