【作者】 刘钢；

【导师】 陈明；

【作者基本信息】 上海交通大学 ， 机械制造及其自动化， 2007， 博士

【摘要】 现代切削技术发展趋势是高效、精密、智能和环保,因而对切削过程中的刀具与被加工工件材料都提出苛刻要求。刀具应该满足高效、高精度、高可靠性和专用化要求,而工件材料应该满足良好切削加工性和环保要求。随着零件使用性能的日益提高,高性能工件材料应用越发广泛,零件结构也越发复杂,这就给切削过程优化带来挑战。同时高性能切削的要求使得刀具和工件材料之间在某些方面产生矛盾,如工件材料较差的切削性能将导致刀具耐用度低和工件加工质量与精度难以保证、薄壁结构件的加工变形对刀具和加工工艺要求苛刻等等,使得切削过程优化越来越迫切。在切削过程优化中,追求的目标及影响切约束随加工方式和加工条件不同而变化,切削过程呈现多目标和多约束特点。针对这一问题,本文应用灰色系统理论,通过构建多约束模型,开展一系列切削过程优化研究,在高效专用刀具开发与应用、高性能工件材料研制、高性能切削中毛刺主动控制及薄壁构件加工变形控制等方面取得创新性成果。主要工作如下:1.首次对切削过程中的多约束描述方法进行了详细分析,解决了如何针对不同的切削条件判断约束对切削过程的影响程度的问题。创新性地利用灰色理论研究切削加工过程中约束描述,分析切削加工过程中多约束的作用机理,建立多约束分析模型。2.首次将多约束描述和切削过程仿真建模以及标准试验的手段结合,研究多约束条件下实际加工过程中工艺和刀具设计可行性,构造工艺参数和刀具参数的可行空间,提出工艺过程和刀具参数的优化策略,为高性能切削提供指导;3.通过对刀具设计进行多约束描述,结合仿真手段和标准试验手段,为刀具结构、涂层以及切削参数提供优化策略,并在淬硬模具钢专用高效铣刀和不锈钢专用高效钻头的设计开发中进行了应用。在此基础上推出了系列涂层模具钢专用高效铣刀和系列不锈钢专用高效钻头,并在市场上获得成功。4.对影响无铅低碳硫系易切削钢切削加工性的元素成分进行多约束描述,研究了材料元素成分及其分布对切削过程的影响,提出有利于材料切削加工性改善的材料设计优化方法。该研究成果应用于某大型钢铁企业,研制出具有良好切削性能的新型易切削钢材料,并推向国内外市场。5.以铝合金铣削加工过程为对象,通过对切削过程中多约束的研究,分别提出针对铝合金切削过程中毛刺和薄壁件加工变形的优化控制策略,并在生产现场进行了成功应用。研究成果应用于某型战斗机铝合金雷达结构件加工和某飞机制造厂平尾梁间整体肋系列零件加工生产线上,使得产品质量和生产效率得到明显提升。更多还原

【Abstract】 The trends of cutting technology are high-efficiency, precision, intelligent and environmental-protection; therefore rigorous requirement has been brought for the cutting tools and workpiece materials. Cutting tools must have the characteristic of high-efficiency, high-precision, well-reliability and specialization; materials with good machinability and less polluted of environment should be guaranteed at the same time. With the development of the manufacturing industry, high performance workpiece materials and complex parts have been widely used, which are becoming a huge challenge to the optimization of cutting process. In particular, the high performance cutting process leads inevitably to the contradiction between the cutting tools and workpieces in some extent, such as: the decrease of tool life, loss of precision and deformation of thin part due to the poor machinability of the workpiece material. Thus optimum cutting process is becoming a critical issue. Goals and constrains of the cutting process change with the cutting conditions, so multi-goals and multi-constrains are the basic characteristic of the cutting process. In this dissertation, gray-system theory is introduced to establish multi-constrained model for cutting optimization. Innovative results have been achieved with the help of this theory, especially in exploitation and utilization of high performance tools, development of high performance materials, initiative-control of burr generation in high speed machining and limitation of deformation in machining thin parts. The main works of this dissertation include:1. The concept of multi-constrained analysis in the cutting process is presented for the first time in the dissertation. The dissertation applies a method to solve an important problem which is how to judge the influence of constraines during cutting processs. The mathematic models of the multi-constrained analysis are built by grey theory, and the multi-constrained system in the cutting process is analyzed in the dissertation.2. The multi-constrained analysis, the simulation of the cutting process and the method of standard experiments are combined in the dissertation for the first time. Focusing on the practical machining process, by means of analysis of different constrains, the feasibility of tool design and technology in the practical machining process are studied. The feasible spaces of the process parameters and tool parameters are constructed and the optimized models are presented, that provided the theoretical basis for the high-performance manufacturing of intricate parts.3. On the basis of the multi-constrained analysis of tool design combined with methods of simulations and standard experiments, the optimum methods are provided for structure, coating and cutting parameters of cutting tools. The research results are applied for development of special milling tools for hardened steel and drills for stainless steel. These products were introduced to the market.4. The multi-constrained analysis of the machinability of nonleaded low carbon sulphur free-cutting steel is studied. The influence of elements to machinability of nonleaded low carbon sulphur free-cutting steel is analysed. The feasible spaces of optimum machinability were constructed, which provided the theoretical basis for the development of new nonleaded low carbon sulphur free-cutting steel. On the basisi of the research results, new free-cutting steels were developed by a large steel company.5. By means of the method of combining the multi-constrained analysis, simulation and standard experiments, the optimum methods for avoiding bur and deformation during milling of aluminum alloy are presented respectively. The optimized instructions are applied successfully in the cutting process of aluminum radar framework of battleplane and rib parts of even tail.更多还原