| With the rapid development of science and technology, high-end CNC machine tools are used widely. As the important basic manufacturing equipment, it is widely used in national defense, marine and aerospace fields. As the finishing processing equipment, the belt-grinding machine is widely used in the finishing processing of various parts, and plays a very important role in product quality control, its level of reliability has a direct impact on the development and competitiveness of our manufacturing industry. In actual production, the reliability of domestic high-end belt-grinding machine is not good and cannot fully meet the business needs, so Chinese high-end belt-grinding machine depends on imports heavily. However, a lot of advanced equipment cannot be imported for a variety of mining restriction governance taken by western countries, which has hindered the development of China's national defense construction and manufacturing seriously. Therefore, it becomes the urgent priority for our country to improve the reliability of high-end belt-grinding machine.This paper was supported by National Major Scientific and Technological Special Project for “The Development and Application of the Adaptive Belt-grinding Centre for Aero-engine Forging Blade”(No.2014ZX04001-031). Regarding a center series domestic belt-grinding as the research object, several theoretical approaches and key technologies of its reliability test technology were studied, the select model of test object and test stress were established, a reliability test design idea was proposed, providing a theoretical basis and technical support for reliability test technology and enriching the content of reliability test technology.The main work and contribution of this paper are as follows:(1) The failure analysis and reliability test system of belt-grinding machine.Through analyzing the field failure data and after-sales data of domestic belt-grinding machine, the failure spectrum of belt-grinding machine was established. The failure location and failure modes and cause of failure of belt-grinding machine were analyzed in-depth, and the failure mechanism of belt-grinding machine was analyzed with qualitative and quantitative methods, laying the foundation for the subsequent study of reliability test. At last, the reliability test in each period of belt-grinding life was analyzed, based on which a reliability test system for belt-grinding was established.(2) The extraction technology of the belt-grinding key features for reliability test.Aiming at lack of theoretical basis for the selection of test object in reliability test, an extraction method of the key features in reliability test based on three-parameter interval gray number was proposed. Based on the definition of the key feature, three-parameter interval gray numbers were used to represent fuzzy information, then fuzzy comprehensive evaluation and projection index function were used synthetically to to solve the problem effectively, combining the field data and expertise.(3) Study on the selection of reliability test stress in the reliability test ofbelt-grinding machine.A fuzzy relationship between the fault and the fault stress was established, and the weight of faults and their fault characteristic attributes was calculated in according with the match model which was based on triangular fuzzy numbers. Then the fault stress was evaluated by the fuzzy comprehensive evaluation method comprehensively. Finally, the reliability test stress for reliability test was preferred according to Pareto Principle, solving the problem how to choose the reliability test stress under the case of failure mechanism model was not established.(4) The reliability test design for the grinding head of belt-grinding machine.In order to conduct a smooth and efficient reliability test, a detailed reliability test design is very necessary. In this paper, a detailed reliability test was designed by taking the grinding head as an example. According to the first failure time of the grinding head, the reliability model was established, which was taken as a basis to select the test time and the test sample size of belt-grinding machine, and then the detailed reliability test design for the grinding head of the belt-grinding machine was carried out combining with the preferred stress combination. This method provided a new idea for the reliability test design. |
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