| With the rapid development of modernization of our country, some major engineering projects, such as water conservancy, transportation, resource development etc., are increasing progressively, and there are large quantities of constructions of tunnels included, which leads to vastly increased demand of tunneling equipment. Boom-type tunnel road header has been widely used in mining, water conservancy, tunnel traffic, urban subway and other major engineering projects, due to its wide universality, wide scope of operation, reducing labor intensity effectively, high efficiency, shortening the project cycle and other advantages. At present, domestic boom-type road headers, mainly used in the coal mine roadway construction, can’t be directly used in the tunnel construction, and there are few of boom-type tunnel road headers in our country, which causes the demand for tunnel construction can’t be met. In order to meet the growing demand of tunnel constructions and breakthrough the foreign monopoly of market and technology, research and development on boom-type tunnel road headers are extremely urgent.Cutting head, being the core component of boom-type tunnel road header, has important effects on working reliability, efficiency, economy and other whole machine performance, therefore, its performance provides important references on the evaluation of machine performance. The design and research on cutting head is the top priority in the research and development of boom-type tunnel road header. However, it’s still lack of scientific and systematic methods and routes on designing cutting head, which leads to high load, large differences of loads, big load fluctuation on picks, short and different lifetime of picks, high energy consumption and low efficiency and other bad results.It must be particularly stressed that there are few research on the cutting head of boom-type tunnel road header, which lack of theoretical foundation and test guidelines. A lot of problems, in cutting head geometry design, cutting parameters of single pick, arrangement of picks and key parameters etc., are still left to solve.In order to reduce energy consumption and spoilage of picks and improve cutting efficiency, the cutting head of XTR260 boom-type hard-rock tunnel road header is designed and researched based on Pro/E-Ansys-LS_Dyna3D Co-Modeling-Solution, with the non-crack-development rock of 12 th grade in strong coefficients as the cutting object. Aiming at the above problems, the main work in this paper is as follows.(1) The structure characteristics and influence on cutting performance are studied to design the geometric structure of the cutting head, on the basic of which, kinetic characteristic of cutting head is analyzed. The mechanical properties of rocks and the mechanism of cutting rocks are studied, and the math model of conical pick cutting rock is established.(2)The theory of simulation on cutting rock is studied. The flow of Pro/E-Ansys-LS_Dyna3D Co-Modeling-Solution is introduced, and the key problems on the solving techniques are intensively study to ensure that the numerical simulation of cutting rock is reliable and accurate.(3)The cutting parameters’ influence on cutting performance is studied so that the evaluation indexes(cutting resistance and its fluctuation coefficient, specific energy consumption) and main influencing factors of are determined. In order to study the influence of various factors on cutting performance, the orthogonal experiment is designed, based on which, the optimal cutting parameters of single pick are determined. In the aspects of time domain, frequency domain and the correlation, the loads on single pick with the optimal cutting parameters is analyzed to ascertain characteristic of loads on single pick when cutting rock.(4)On the clear knowing of the principle of picks’ arrangement, the characteristics of different arrangement types are analyzed and the number of picks and the relative position between adjacent picks are detailed. After the helix related parameters on cutting performance analyzed, the helix angle is determined. The theoretical value of space between cutting lines, which is the most important parameter in picks’ arrangement, is given. The Simulation models of multi-picks cutting rock of different arrangements are established, through which, the cutting performance of multi-picks is studied to determine the optimal value of space between cutting lines. Thereby, the best pick’s arrangement for cutting head is determined.According to the results of the research above, the cutting head of XTR260 is finally designed out. |
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