【作者】 程耀楠；

【导师】 李振加；

【作者基本信息】 哈尔滨理工大学 ， 机械制造及其自动化， 2008， 博士

【摘要】 金属切削加工是机械工业中的基本工艺方法,刀具是金属切削加工中的主要工具,刀具在很大程度上影响着机械产品的质量与可靠性。随着刀片材料及其制造技术的发展,具有复杂槽型的新型硬质合金铣刀片不断出现,三维复杂槽型铣刀刀片的应用日益广泛。目前国内外研制的铣刀片槽型多是以经验加试验的方法定型的,缺乏理论研究基础,槽型的优劣没有统一的判断依据。因此,进行三维复杂槽型铣刀片槽型优化原理与优化技术的研究,以解决自动化生产中刀具破损这一关键技术问题,保证FMS、CIMS等先进制造系统的正常运行。因此,本课题从提高三维复杂槽型铣刀片的切削性能和可靠性出发,建立三维复杂槽型铣刀片表面受力、受热密度函数数学模型;以表面受力、受热密度函数为边界条件进行三维复杂槽型铣刀片应力场、温度场及其耦合物理场的有限元分析,并对三维应力场和温度场及其耦合场进行模糊数学评判;在实验的基础上,进行三维复杂槽型铣刀片冲击破损和粘结破损的试验研究;以最小刀具破损为目标进行优化目标函数的建立,为建立三维复杂槽型铣刀片槽型优化CAD系统打下基础。首先,在已建立的三维复杂槽型铣刀片铣削力数学模型基础上,进行大量、系统的切削实验,建立铣削力的实验式以及刀-屑接触长度与接触宽度的实验式,从而建立三维复杂槽型波形刃铣刀片的表面受力密度函数数学模型,并进行定量计算对其分布规律进行分析,为三维应力场的分析研究奠定基础。其次,在已建立的三维复杂槽型铣刀片表面受力密度函数数学模型基础上,对平前刀面铣刀片和波形刃铣刀片进行了三维应力场有限元分析,并对有限元分析结果进行模糊数学综合评判。根据波形刃铣刀片表面受力密度函数分布规律及在铣削周期内的受力分析,应用弹性力学方法,采用双调和方程进行三维复杂槽型铣刀片切入过程应力状态分析。第三,针对不同的槽型及刀片材质进行铣刀片冲击破损实验,对比分析几种槽型铣刀片破损形貌。采用数理统计的方法建立几种铣刀片冲击破损寿命累积分布函数数学模型,进行冲击破损寿命比较分析,从而对铣刀片三维应力场有限元分析的结果进行检验。第四,在已建立的三维复杂槽型铣刀片铣削温度数学模型基础上,采用人工热电偶法测量刀-屑接触面的铣削温度,建立前刀面刀-屑接触区的平均温度与时间之间的实验方程式,从而建立铣刀片表面受热密度函数与温度场数学模型。以受热密度函数为边界条件,进行波形刃铣刀片和平前刀面铣刀片三维温度场有限元分析,并对有限元分析结果进行模糊数学综合评判。进行三维复杂槽型铣刀片粘结破损量化数学模型的研究,建立前刀面刀-屑接触区铣削温度与最大粘结破损深度的关系,从而可以根据铣刀片前刀面上的最高温度,预测其粘结破损情况。最后,对平前刀面铣刀片和波形刃铣刀片的温度场和应力场进行热-应力耦合场分析,探讨耦合情况下等效应力的分布规律和受力变形状况,并对平前刀面铣刀片和波形刃铣刀片的耦合场进行模糊数学综合评判。以最小冲击破损和粘结破损为目标,建立应力场模糊综合评判结果与背吃刀量之间的目标函数关系和温度场模糊综合评判结果与背吃刀量之间的目标函数关系,运用优化理论对目标函数进行优化,为设计和开发新槽型提供理论依据。更多还原

【Abstract】 Metal cutting machining is the basic technical method in mechanical industry, and the cutter is the primary tool in the metal cutting machining. The cutter affects the quality and reliability of the mechanical products to a large extent. Along with the development of the insert material and its manufacturing technology, new hard alloy milling inserts with complex grooves come forth continually, and the milling inserts with complex three-dimension (3D) grooves are increasingly applied widely. At present, the grooves of milling inserts developed by domestic and oversea manufacturer are mostly finalized the design with the experiential and experimental methods and shortage of theoretic study basis. The groove has no uniform judgement basis. Thus, in order to solve the cutter disrepair that is the key technical problem in automatization production, and ensure that the advanced manufacturing systems run normally, such as FMS, CIMS, study on groove optimization principle and technology of complex 3D grooves milling insert should be done. The study work has very important theory significance and practical value.In order to improve the cutting capability and reliability of complex 3D grooves milling insert, the force and heat density function mathematical models are built. The force and heat density functions are looked as the boundary conditions and the stress fields, temperature fields and their coupling fields of complex 3D grooves milling inserts are analyzed with the finite element analysis (FEA) method and judged with blurry mathematical theory. The impact disrepair and adhering disrepair of complex 3D grooves milling insert are studied based on experiments. Aimed at the minimal disrepair, the optimization object functions are built. So to provide the basis for the groove optimization CAD system of complex 3D grooves milling insert.Firstly, based on the milling force mathematical model of complex 3D grooves milling insert, the experimental formulas of milling force and contact length and width of cutter-chip are built with a plentiful systemic cutting experiments. Then the force density function mathematical model is built, and is calculated quantificationally to analyse its distributing principle. The studies poivide a basis for the 3D stress field analysis.Secondly, based on the force density function mathematical model of complex 3D grooves milling insert, the stress fields of the waved-edge milling insert and flat rake face milling insert are analyzed with FEA method and judged with blurry mathematical theory. According to the distributing principle of the waved-edge milling insert and force analysis in the cutting periods, the double unison equation is introduced to analyse the stress state of cut-in course with the elasticity mechanics method.Thirdly, the impact disrepair experiments with different grooves and insert materials have been done, the disrepair shapes are compared among the several types of grooves milling inserts. The impact disrepair life cumulating distribution function mathematical models of them are built by the mathematics statistic method and the contrast analysis of the impact disrepair average lives bave been done among them. So to verify the FEA results of the 3D stress field of the milling inserts.Fourthly, based on the milling temperature mathematical model of complex 3D grooves milling insert, the milling temperature of the cutter-chip contact interface is tested by the manual thermocouple method. The experimental formulas are built, which are the average temperatures of the cutter-chip contact area on rake face to time. The heat density function and temperature field mathematical models are built. The heat density functions are looked as the boundary conditions and the 3D temperature fields of the waved-edge milling insert and flat rake face milling insert are analyzed with FEA method and judged with blurry mathematical theory. The mathematical model of the adhering disrepair is studied for complex 3D grooves milling insert. The relations between milling temperature of cutter-chip contact area on the rake face and the maximal adhering disrepair depth are built. According to the maximal temperature on the rake face, the adhering disrepair could be forecasted.Lastly, the heat-stress coupling field between the stress field and temperature field of the waved-edge milling insert and flat rake face milling insert is analyzed to discuss the distributing principle of equivalent stress and its distortion under the coupling condition. Aimed at the minimal impact disrepair and adhering disrepair, the function relations between the blurry judgement results of stress field and the cutting depth, and the function relations between the blurry judgement results of temperature field and the cutting depth are built. The object function is optimized by the optimization theory to provide theoretic basis for designing and developing new grooves.更多还原