| As an important process equipment for energy conversion in the process of power generation,steam turbine blade is the "heart" of steam turbine.But the manufacturing process of steam turbine blade is more complex,so the structure of the blade fixture also has some complexity.Selecting a suitable clamp can shorten the production preparation period of the blade.At the same time,there are many kinds of turbine blades,and the difficulty of fixture design also increases.How to design the new fixture according to the existing experience,shorten the design time,improve the standard degree of fixture design has become the focus of enterprise research.In view of the present situation,this paper launches a research on the design method of turbine blade fixture based on rules.Combined with the manufacturing process of turbine blade,it focuses on the design process of fixture.The main contents are as follows:(1)By studying the characteristics and composition of blade and fixture,combined with rule-based reasoning method,the overall framework of the design method of turbine blade fixture is constructed.(2)The selection of positioning mode and clamping mode under different working conditions is introduced in detail,and SQL2014 is used to build the corresponding rule base.Through rule reasoning,the clamping information is obtained.The fixture parts are divided into serialized parts and parameterized parts,and the serialized parts library and parameterized parts library are constructed by part family method and expression method respectively.And in order to improve the efficiency,the jig component library is established,and the 3D model of the parts is stored,which conforms to the logic of the jig design system,and the calling program of the parts is verified by a concrete example.(3)Obtaining assembly information of parts through rule-based reasoning method to determine assembly surface of components and corresponding assembly features.According to different assembly features,appropriate constraint relations are selected to carry out assembly,intelligent assembly based on feature rules is completed,and the assembled fixture is stored in the fixture instance library.(4)In order to call the existing instance,build the fixture instance system based on code.Starting from the function of the fixture,the function information is set to different weights,and the different weights are divided into different levels through the analytic hierarchy process,which makes the calculation of similarity more intuitive and scientific.Finally,through the nearest neighbor index method to complete the retrieval of the fixture instance,according to the specific design requirements of the parts are modified,modified information top-down drive to complete the detailed design of each part,get the desired fixture.(5)Study the secondary development technology of UG,write relevant programs,and integrate with UG platform,and verify the feasibility of the design method proposed in this paper with concrete examples.In this paper,a rule-based design method of steam turbine blade fixture is put forward based on the practice and the design experience of enterprises.It can greatly reduce the repetitive work of designers,improve design efficiency,make fixture design more standardized,meet the needs of enterprises for fixture design,and increase the competitiveness of enterprises. |
