| Blade structure is more complex, less stiffness, and its material is difficult to processing. But its machining precision is relatively high. These have increased the difficulty of blade machining. At present, many blade factories still adopt the traditional hand-made machining and grinding blades in our country, especially in the blade profile finishing process. Because of the lower precision and efficiency of this backward grinding way, it’s needed urgently to develop blade CNC belt grinding machine to improve processing quality and efficiency of the kind of complex curved surface parts, like the blades. In this paper, it realized the blades precision processing with highly efficient abrasive belt grinding and advanced numerical control technology, designed the structure of six-axis CNC blade belt grinding machine based on the study of blade surface belt grinding process. In order to improve the static and dynamic performance of grinding machine and reduce the weight of the grinder, the structural analysis and design optimization of grinding machine were completed. The main contents in this paper are as following:Firstly, based on the shape of the blade structure, material characteristics and the characteristics of the belt grinding, the basic movement of the blade surface belt grinding was analysed, the number of motion control axes of the developed blade belt grinding was identified, and on the basis, the structure type and configuration of the grinding machine was discussed. According to the shape dimension of blade and the belt grinding process requirement, the stroke and velocity of each motion axes of the belt grinding machine were determined. Based on the determined structure configuration and structural function parameters of the grinding machine, the overall structure of the grinding machine were designed in detail, including the main components of machine tool and grinding systems.After the structural design of the grinding machine completed, static and modal analysis was made to obtain static and dynamic structure performance of the grinding machine. In this article, static analysis of the key components of the grinding machine was firstly completed, such as the grinder bed, slide, column, carriage and grinding turning pedestal, and based on the analysis results of each part, their structures had been improved. After the modal analysis of each part made, dynamic property of the improved structure was compared with the original design. Consider the impact of the joint surface, static and modal analysis of the grinder structure was completed, and the analysis result of the impoved grinding machine structure was compared with the original structure. Compared to the previous structure, the improved structure has less quality, but the static structural performance of the grinder is greatly improved, and the first few natural frequency of the grinding machine have little change, that is to say, the dynamic structural properties of the grinding machine keep the same as the original structure.In the last chapter of the paper, compared to other parts, the dynamic performance of the grinder column is relatively weak, and in order to improve the dynamic performance of grinding machines, the structure topology optimization of the column was made. In the optimization, topology optimization problems were carried out which based on different optimal objectives all subjected to volume constraint: the structure compliance of the grinder and the first natural frequency. After the structure ananlysis of the optimized column, its static and dynamic performance had compared with the original structure design. Comparative results show that the important structural performance parameters of the optimized column structure has a more substantial increase, such as structural rigidity, mass ratio and the first natural frequency. |
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