Research On Valve Product Assembly Quality Modeling Technology And Evaluation Method

The valve industry is an important part of the equipment manufacturing industry.The valve industry is of great significance for improving the level of equipment manufacturing and promoting the development of the industrial economy.The valve product is a control component that controls the direction and pressure of the fluid in the pipeline fluid delivery system.It plays a pivotal role in the national machinery and equipment.The assembly process,as the last link in the production of the entire product,directly determines the level of product quality.This paper takes valve products as the research object,and systematically studies the modeling and analysis of valve product assembly quality.It provides new ideas for the application and research of valve product assembly process quality control technology.This paper is supported by“Research on Multi-state Quality Data Flow Modeling and Predictive Control Method for Complex Product Assembly Process”(National Natural Science Foundation,No.71671130).By the theories on the assembly quality of valve products are studied under the support of the grant,we put forward the assembly quality modeling techniques and evaluation methods.Topics covered in this dissertation are as follows:(1)The basic theory of valve product assembly quality is expounded.The significance and purpose of modeling and analysis of different assembly stages of valve products are analyzed.The contents of the valve product assembly process quality analysis,assembly quality inspection project sequencing and assembly quality evaluation are studied.The valve product assembly quality modeling technology and evaluation system was constructed.(2)Aiming at the complex factors affecting the assembly process in the assembly process of valve products,the quality of assembly process is difficult to quantify.The quality modeling analysis of assembly process based on GO-FLOW method and FTA method is proposed.According to the relationship between the assembly quality of the valve product and the formation process of the product assembly quality,the product assembly quality analysis is transformed into the analysis of the assembly process in the product assembly process.The GO-FLOW model of the valve assembly process was established by introducing the GO-FLOW method.The GO-FLOW calculation method is used to calculate the reliability of the valve assembly process.Then,based on the calculation results,the FTA analysis model is constructed to analyze the assembly process of the product.(3)In order to sort the valve product assembly quality inspection items,the specific links and quality inspection contents of assembly quality inspection were analyzed.For the valve product specifications,the detection content of different specifications of products is not the same,the assembly quality inspection process is not easy to control and other issues.A method based on entropy weight and approximation and Technique for Order Preference by Similarity to Ideal Solution is proposed to rank the inspection indexes of valve assembly quality.According to the data of product quality inspection,the entropy weight of the item index of assembly quality inspection is calculated.The TOPSIS method is used to optimize the assembly quality inspection process of valve products.(4)In order to meet the requirements of valve product assembly quality evaluation,this paper conducts an in-depth analysis of the valve assembly quality evaluation index system,and establishes the layered analysis evaluation model for valve assembly quality evaluation.The comprehensive analysis and evaluation of the assembly quality of the whole machine is carried out by the improved analytic hierarchy process(IAHP).Finally,an example is given to prove the effectiveness of the analytical method in the evaluation of valve product assembly quality.