| In recent years,China's economic development is very rapid,so as to the growing demand for energy in the industry.Coal is a very important source of energy.Road-header is mainly used for cutting and breaking rock,what is convenient for coal mining.Therefore,the development of the road-header,especially the development of heavy mining machinery,has become a top priority.Boring machine mainly work in the mine or underground,and when it is working the cutting head has to bear the work load which changes Easily,It is easy to cause the vibration of the components,which may affect the normal working.The electric cabinet is located in the rear support,it is easy to produce vibration,vibration and even lead to internal components failure.Therefore,it is necessary to study the dynamic performance of the system,so as to control the mechanical vibration through the dynamic analysis,and then can it meet the requirements of the stability of the work.The dynamic simulation of the road-header and the vibration reduction design of the electric cabinet were carried out in this paper.First of all,the paper established a simplified model of the road-header in UG and got the stress,deformation and modal characteristics of the structure by carrying on the analysis of the modal.The analysis of the influence of each part to the electric cabinet provided the basis for the subsequent analysis of vibration.The top of the cutting head and the tail of the conveyor and the hydraulic cylinders were most likely to deform.The deformation of the electric cabinet mainly occurred in the range of 50 Hz-65 Hz,90 Hz,116Hz,and the vibration isolation design of the electric control box should pay particular attention to the damping effect of these frequency bands.Then,UG was utilized to establish the model of the cutting head,and the simulation about transverse cutting rock was carried out in finite element software ANSYS/LS-DYNA,the work force and acceleration of the cutting head at different pitch angle were obtained.Based on the above analysis,the vibration of the cutting head was analyzed,which lay the foundation for the vibration analysis of the whole machine and the design of the vibration control of the electric cabinet.The work force and torque obtained from the process of cutting were exerted on the cutting head of the whole model of road-header,the transient dynamics analysis of the whole model was carried out in finite element software,and then got the dynamic response of each component,and then can view its influence on the vibration of the electric cabinet.After that,the model of the existing vibration damping system of electric cabinet was built,and the harmonic response analysis was carried out.It was found that the vibration of the vertical direction of the electric cabinet is the most serious.Through the analysis of the frequency domain curve,it could be found that it is 71 Hz when the electric cabinet and input load to achieve resonance.Based on this,the two stage vibration reduction design was proposed.Based on the analysis of structural parametric harmonic response,the location of the second stage vibration isolation cushion was found.By comparing of the vibration response of the electric cabinet in the design of the two stage vibration reduction design that optimization with the result in the existing vibration damping system,it showed that the effect of the two stage vibration reduction design was better than the existing vibration reduction design. |
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