| This dissertation extensively studies on the structure design methodology and makes remarkable progress to solve the bottlelneck problem of design from mechanism sketch to structural scheme in machine tools.The work is supported by the National Natural Science Foundation of China(No.51275067 and No.51375065),National Key Technology Research and Development(No.2011BAF11B03),and National Science and Technology Major Project(No.2012ZX04010-011-03).The design methodology established in the dissertation has been adopted by many kinds of machine tools in Dalian Mechine Tools Group,Shenyang Mechine Tools Group and so on.The main research contents are as follows:(1)On structure configuration design and static accuracy model of mechine tool.From kinemactic chain,established the correlation matrix between the links and the kinematic pairs,proposed the orientation matrix representing the relative position relationship between the adjacent links,constructed the structural configurations by means of frame inversion and Boolean operation of the orientation matrixs;conbining with the geometric parameters of all links,built the mechanical model and static accuracy model of machine tool to solve the loads of each connecting surface for providing the load condition for the following structural scheme design.(2)On structural scheme design of kinematic pairs and mechanismic units.Studying the essence of motion constraints and structural schemes of kinematic pairs to establish constraint vectors of geometric elements of points,lines and planes,defined the operation rule of the constraint vectors;through the calculation,decomposition and matching of constraint vectors,constructed the structural schemes of kinematic pairs;introducing connection matrix,achieved the structural schemes of the screw feeding mechanism and spindle slewing unit.It provides an effective way for the structure design of kinematic pairs and mechanismic units.(3)On structural scheme design of typical elements.Converting the problem of a like structure design into a load path optimization problem of continuous geometric structure cosidering its join surfaces,first time proposed a conceptual-structural design method of complex mechine elements,consisting of four steps,building a geometric-physical model,extracting a conceptual model,meeting the strength and stiffness requirements,and considering structural manufacturability and aesthetics.Using this method,the structural design schemes of 5 typical parts are accomplished,which include headstock,column,bed,slider and table of the vertical machining center.(4)On structure scheme and performance analysis of an overall machine tool,puting forward the structure scheme design method of machine tool.Setting up the relationship between the three aspects of the machine tool structure configuration,structure schemes of kinematic pairs and mechanismic units to generate typical parts structure schemes,bulit the structure scheme matrix and construct the whole structure scheme of machine tool;At the same time,established the mechanism model of static displacement vector,and analyzed the structural performance of the spindle unit and machine tool,including static deformation and dynamic characteristics.It makes a very meaningful exploration for the structure design of machine tool about accuracy and performance.(5)On performance measurement of machine tool and mechanismic units.In term of the typical operating position of the work space,analyzing the test principles of the static and dynamic performance,designed the corresponding testing program.The measurement results of performance measurement show that the structure meets the design requirements.The performance measurement of spindle unit shows that spindle unit structure meets its design requirements.Comparing with the results of calculation and measurement,the rationality and validity of the structural design methodology,structural scheme and calculation model are verified. |
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