Temperature Analysis And Optimization Of Disc Hob Based On ANSYS

The rapid development of China's economy has led to an increasingly serious phenomenon of population urbanization,which has brought about a series of traffic problems.In order to solve the traffic problem,major cities are constructing underground traffic tracks.Considering environmental and ecological factors,the shield method is more and more used in urban traffic.Although China has already realized the local production of shield machines,there are still many shortcomings in the manufacture of some key components.The hob is the core component of the shield rock breaking rock.Its working state will directly affect the construction progress and cost of the whole shield.Therefore,the analysis of the hob is of great significance to improve the life of the hob.The friction between the hob and the rock causes the temperature of the hob to rise.As the temperature increases,the thermal strain and strain of the tool will cause micro-cracking on the surface of the cutter ring,which will aggravate the wear,fatigue damage and reduce the tool life.In this paper,by studying the temperature field of the hob,the optimization method is proposed and analyzed,aiming at reducing the wear of the blade during rock breaking and improving the service life of the hob.The specific research contents of this paper are as follows:(1)In this paper,the installation position of the hob is studied by the classification of the hob,then the structure of the hob is analyzed,the CAD drawing is drawn,and then the mechanism of the hob force and the rock breaking mechanism are analyzed,which is the temperature field simulation of the hob.And optimization provides theoretical support.(2)Combined with the study of friction mechanism,the effects of normal pressure,sliding speed and temperature on the friction coefficient were analyzed.The calculation method of the friction heat of the hob and the way of the heat loss of the hob are analyzed,which provides theoretical support for the establishment of the temperature field model.(3)A brief introduction to ANSYS finite element analysis software.The influence of tool material properties on the hob temperature is analyzed,which provides a theoretical basis for the selection of hob materials during simulation.Combined with the frictional heat analysis,a three-dimensional finite element model of the hob temperature field was built.The distribution law of the temperature field of the hob and the influence of the penetration degree and the cutter disk speed on the temperature field of the disk hob were obtained.Through the experimental analysis of the relationship between the excavation parameters and the hob temperature field,the relationship between the hob temperature and the penetration and the change of the cutter wheel speed is obtained,and the correctness of the numerical simulation of the temperature field is verified.(4)By studying the relationship between the rock breaking force and the temperature field of the disc hob,combined with the heating mechanism of the hob,the relationship between the friction heat and the diameter,penetration and cutting angle of the hob is analyzed.It is concluded that the temperature has the best advantage,which makes the rock breaking efficiency the highest,and provides guidance for the selection of parameters during the tunneling process.By calculating the wearable volume of the different diameter hob cutters,it is found that the method of reducing the diameter of the hob by reducing the diameter is not feasible.A method to reduce the temperature of the hob by reducing the blade angle is proposed.The finite element simulation is used to compare the results before and after optimization to verify the correctness of the theoretical analysis.