The Cnc Machining of Spacecraft Shell
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The research in this article has the following significance in practical applications:
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Spacecraft shell parts are one of the core structural parts of the spacecraft. They are mainly cone and column shells with a diameter of less than 1300mm and a height of less than 1700mm. The material used is mainly forged and cast aluminum alloy, which bears the role of connection and support. According to the positional relationship of each functional element of the spacecraft in space, it can coordinate movement. As different types of spacecraft undertake a variety of tasks, they carry different functional components, resulting in various types of spacecraft shell parts. As shown in Figure 1-1, there are three typical spacecraft shell parts. .
During the “13th Five-Year Plan” period, with the rapid increase in space missions, the demand for spacecraft shell parts has increased sharply.
add. Compared with general mechanical products, spacecraft shell parts have the characteristics of small batches, multiple varieties, short cycle times, and quick product replacement. During the production process, problems such as uneven task distribution and periodic shortage of manufacturing resources continue to appear. Traditional The low-flexibility, large-scale production model of the company has been unable to meet the current development needs of multiple models and high-density simultaneous development.
Nowadays, with the rapid development of the aerospace manufacturing industry, the manufacturing workshop of spacecraft shell parts has reached a certain level of digitalization. With the use of CNC machining centers, automatic guided AGVs and other hardware facilities, CNC storage systems, and digital manufacturing execution systems , Workshop data acquisition system and other management analysis software based on the “digital shell production line” structure is becoming more and more perfect, the machining efficiency of parts has gradually improved, and the machining quality has also been better guaranteed. However, the machining process design process of the spacecraft shell parts still adopts the traditional method, relying solely on the artificial design by the craftsman, which limits the improvement of the manufacturing level. After analysis, the traditional machining process.
The design method mainly has the following two drawbacks:
- (1) High technical requirements. Machining process route planning needs to consider the various attributes of the product. Compared with other mechanical products, the manufacturing requirements of spacecraft shell parts are more complicated, requiring technicians to have professional knowledge reserves and be familiar with the manufacturing resources of the workshop. In addition, the characteristics of short cycle and fast replacement also require process personnel to quickly design an effective process route.
- (2) The process design efficiency is low and the cost is high. When designing the process route, the process personnel need to read a large number of production guidelines, drawings and process manuals in order to obtain the process knowledge contained in the parts. The tasks are cumbersome and there are many repetitive tasks. In particular, the structure of the spacecraft shell parts is complex and the number of features is large, and there is an urgent need for related technologies to support rapid retrieval of process knowledge.
In the product production cycle, machining process design is the bridge connecting design and manufacturing. For manufacturing enterprises, machining process design is its soul, and its design capability is the core capability of an enterprise to maintain its competitive advantage. An effective machining process design method or technology can effectively improve product quality, shorten product cycle, and reduce production costs. Therefore, the intelligentization of the machining process design of the spacecraft shell parts is a key factor to improve the manufacturing level.
Through the analysis of the problems existing in the traditional design methods, it is found that the fundamental reasons that restrict the efficient and high-quality design of the machining process of the spacecraft shell parts are:
- (1) Historical process data has not been effectively used. In the process of part design and manufacturing, a large amount of process data will be generated, and most of these historical process data have not been effectively stored and used, which is mainly reflected in: there is no standardized storage, which makes it difficult for process personnel to retrieve relevant knowledge for reference during the design process; The lack of appropriate process knowledge mining methods has led to the inability to effectively use historical process data to guide rapid decision-making of machining methods.
- (2) The level of intelligence in the process route planning is low. The current CAPP technology is still in the stage of development and improvement, and the process route is still mainly planned by process personnel based on process knowledge. Spacecraft shell parts have the characteristics of high integration of features. Although the functions and structures of the parts are diverse, the features of the components have great similarities.
They are mainly composed of more than 10 typical shell shapes, inner shapes, windows, and grids. Machining features and a number of uncommon atypical machining features. At the same time, due to the similarity of the machining requirements such as the materials and precision of the typical features of the parts, the machining methods of the features of different parts can be used for reference. Therefore, the machining process knowledge can be linked based on the machining characteristics, and the machining methods in the historical process data can be excavated and pushed to the process personnel, thereby improving the retrieval efficiency of the process personnel, and enabling the process personnel to quickly and effectively guide the design work .
In addition, in the process of machining process design, process personnel must not only consider the feasibility of the process route, but also minimize the machining cost. However, the number of features of the spacecraft shell parts is large, and the digital workshop has a wide range of equipment machining and strong capabilities. Technologists need to select appropriate machining methods and manufacturing resources for machining features under the constraints of process rules, and group them into process steps. The process steps are sorted rationally, so as to organize them into economical and practical process routes. Obviously, compared with general mechanical parts, the task of planning the process route of the spacecraft shell parts is more difficult and requires higher abilities of the process personnel. Therefore, it is possible to improve the speed of the process route planning and reduce the calculation burden of the process personnel through the research of the process route planning technology based on the intelligent algorithm.
Therefore, in order to adapt to the “multi-type, small-batch” production mode of spacecraft shell parts, improve the process
The utilization of historical data and the intelligent level of process route planning. This article will take the machining process design of typical spacecraft shell parts as the research background, and analyze the machining process knowledge during the design process and the inherent relationship between the knowledge. Guide the modeling of the machining process knowledge network. On this basis, rough set theory is introduced to mine the potential process decision rules in the process history data, so as to quickly obtain the machining method of the machining characteristics according to the decision rules for the reference of the process personnel. Finally, study the process route planning method under the constraint of process rules to improve the intelligent level of process route planning. According to engineering practice, due to the small number of atypical parts and atypical features, the reusability is not high.
Based on the machining process design of typical shell parts of spacecraft, this paper re-organizes the internal relationship of machining process knowledge and establishes a process knowledge network model with a clear organization form, which provides convenience for the retrieval and reuse of process knowledge; research process The mining method of decision rules can make full use of empirical knowledge to guide the decision-making of machining methods; improve the intelligent level of process design by studying the process route planning method based on specific immune algorithm; and apply the above theoretical methods and technology research and practice Develop a tool for extracting manufacturing features of typical spacecraft parts, a tool for mining and extracting process decision rules, and an intelligent planning tool for process routes to improve the process design efficiency and intelligence level of typical spacecraft shell parts.
Trang liên quan:Aircraft Parts
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