| With the accelerated development of domestic urban economic development and construction,more and more provinces,cities and rural areas have also accelerated the development and utilization efficiency of land.Under this background,the function of tunnel full-face tunneling machine(referred to as “TBM” in English)is also constantly improved.With the excellent technical characteristics of mechatronics,TBM not only plays an important role in the equipment manufacturing market,but also is widely used in many engineering fields in China.When carrying out underground construction projects,the TBM will need to excavate and develop more difficult and complex land structures.Based on the differences in domestic geographic space and soil quality,people have more serious requirements on the rigidity,service life and load capacity of the TBM.In the actual operation process,the construction progress of the project is directly related to the final benefit,and it is also an evaluation index for the quality of the inspection project.At present,relevant domestic practice shows that the design and performance characteristics of the cutter head and disc cutter of the TBM are directly related to the operating efficiency of the machine and the service life of the equipment.Therefore,strengthening the design and reasonable layout of the disc cutter performance of the equipment is the key point to improve the performance of the TBM and promote the progress of the project construction.It not only relates to the productivity of the enterprise,but also helps the enterprise to save costs and enhance the competitive advantage of the market.In the process of actual operation,if the tool control system of the TBM fails,it will not only affect the operation efficiency of the equipment,but also bring serious risks.The rolling force of the disc cutter is the main parameter reflecting the rock breaking efficiency.In view of this,this topic focuses on the discussion of the rolling force and rock breaking specific energy of the disc cutter,and seeks for the optimal penetration,cutter spacing and rolling line speed,so as to improve the stable operation and safety of the cutter and operating system.Based on the theoretical research of the predecessors,this thesis discusses the actual development and application of the TBM in the domestic and foreign markets,and carries out the simulation and experimental tests of the disc-shaped double cutter in order to improve the cutting precision and working efficiency of the double cutter to verify the impact of the excavation parameters on the rock breaking efficiency of the cutter.The following content shows the research focus of this topic:(1)The research background and significance of the project are put forward.Summarized the development history and research status of full-section hard rock roadheader at home and abroad,and recognized the great achievements and development of China in TBM.(2)The classification and structure of the disc cutter are introduced.The rock breaking mechanism under the action of the cutter is studied.The whole stage of the rock fracture and the complete occurrence of the rock to the crack is analyzed.The force prediction formulas of the cutter are summarized: Evans formula,Qiu Sansou Saburo formula,Colorado Institute of Mines formula and North China Institute of Hydropower Formula.Based on the elastoplastic strength criterion of the rock,the stress failure mode of the rock breaking stage was explored,and a calculation method of the rock breaking amount and a method of calculating specific energy were proposed,which provided a theoretical basis for subsequent simulation analysis and experimental research.(3)The paper proposes to use ABAQUS software to study the influence of penetration and rolling line speed on the rolling force and rock breaking specific energy of the cutter.The structural parameters of the disc cutter and the rock material parameters are set,and the finite element model of the disc-shaped double cutter breaking rock is established.The rock-breaking process of the double cutter is simulated and analyzed.Under the action of the hob,the relationship between the different penetration,rolling line speed on rolling force and rock breaking specific energy are studied,and a reasonable penetration and rolling line speed are obtained.It improves the rock breaking efficiency of the cutter and provides technical support for optimizing the cutter head arrangement.(4)The cutter spacing of the disc double cutter in the finite element model is studied.Based on the influence of the rolling force and the rock breaking capacity on the comparison of the cutter spacing,the average rolling force and the rock breaking amount of the disc double cutter are obtained by changing the single variable.The curve of the cutter spacing intuitively reflects the relationship between the cutter pitch and the specific energy of the cutter and the rock breaking efficiency,and the optimal tool spacing is obtained.The research results provide a basic theoretical basis for rationally arranging the cutter spacing and improving the rock breaking efficiency of the disc cutter.(5)The double-chopper rock breaking test platform of North Heavy Industry Group Co.,Ltd(The article is referred to simply as NHI)was used to carry out experimental analysis,and the different parameters were set to analyze the cutter spacing,the penetration degree and the rolling line speed,and experiments were carried out on different rock types.Therefore,the influence of the cutter pitch,the penetration speed and the rolling linear velocity on the rolling force and rock breaking specific energy is obtained,the test results verify data from double cutter rock breaking simulation,and the relationship between the rock type and the surface fracture is analyzed.Through experimental verification,including the simulation mechanism and technical analysis of the cutting mechanism and force degree of the boring machine disc cutter,which reduces the energy loss,increases the rock crushing amount,and optimizes the boring machine for optimizing the cutter parameter design.The working performance and the work efficiency of the disc cutter breaking rock provide better technical support. |
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