折线刃球头铣刀刀片的磨削方法

球头立铣刀刀刃曲线形状直接影响其切削性能和制造工艺,直线刃球头铣刀刀片易于刃磨,但切削性能差;螺旋刃切削性能好,但刃磨难度大,加工成本较高。分段直线刃搭接的折线刃球头铣刀刀片,既改善了直线刃的切削性能,又可在周边磨床上高效磨削,实现低成本制造。     

S形刃球头立铣刀的数学模型

建立了S形刃球头立铣刀内前刀面、外前刀面及螺旋后刀面、平面后刀面的数学模型。该模型的建立为球头立铣刀刃磨参数选择及刃磨装置设计具有重要的作用。     

球头铣刀刀具磨损建模与误差补偿

针对刀具磨损度量方式和模型建立的问题,以球头刀具为研究对象,提出球头铣刀刀具磨损的度量方式,建立球头刀具磨损模型.以复映磨损在硬度较软加工材料上的方式测量球头刀具磨损,确定刀具磨损模型系数,给出刀具磨损模型系数确定的具体实现方法.加工试验验证球头刀具磨损度量方式的合理性和所建立刀具磨损模型的正确性,同时针对数控铣削加工中球头铣刀刀具磨损引起的误差提出离线仿真误差补偿算法,给出离线仿真误差补偿算法的具体实现步骤,通过建立的刀具磨损引起的加工误差模型仿真获得加工走刀步的误差.对于误差超差的走刀步,预先修改数控加工(Numerical control,NC)程序,保证实际加工零件满足精度要求.误差补偿验证试验表明所提出的离线仿真误差补偿算法的正确性和有效性.     

一种空间曲线刃球头铣刀的设计

介绍了一种新型空间曲线刃球头铣刀的刃形特征和切削优点,详细分析了其空间几何参数的计算方法,简要说明了其制造工艺。     

曲线刃滚切刀的刃形分析与建模

经过研究,建立了滚切刀曲线刃的数学模型,为该刀的加工提供了依据。     

大型风电传动齿轮成形铣削刀具刃形曲线设计

基于成形原理加工齿轮廓形的盘铣刀是生产大型风电传动齿轮的必备刀具。然而,受加工原理误差影响,传统齿轮盘铣刀只能针对特定模数和齿数齿轮进行加工,刀具通用性差。传统刀具廓形不能够保证被加工齿轮的加工精度与使用寿命,无法最大程度发挥成形铣削的原理优势。基于此建立了齿轮渐开线实际廓形曲线数学模型,分析了共轭齿条顶角相对运动轨迹,建立了齿根过渡曲线方程,依据齿根过渡圆弧空间相对位置,重构了不同形式齿廓曲线的设计方式;基于逆向投影法,以被加工齿轮的各项参数为变量,建立了刀片刃形曲线数学模型,根据刀片空间包络原理,重构了可转位齿轮盘铣刀廓形曲线设计方式;进行了齿轮齿廓及刀片刃形曲线数值分析,研究了大型风电传动齿轮齿廓曲线以及可转位齿轮盘铣刀刀片刃形曲线的主要形式,研究结果为大型齿轮廓形成型加工提供技术支持。     

球头刀刃几何建模中参数选取的分析

在描述球头刀刃的曲线参数方程时 ,选取不同的刀刃几何参数会影响刀刃槽加工的刀位轨迹非线性方程计算中的求解 ,产生求导病态以及坐标变换中的几何不变性等问题 ,本文依据微分几何和计算几何理论阐述了以刀刃点的转角变量作为刀刃几何参数的优越性。     

球头立铣刀端刃前刀面的刃磨仿真

以Solidworks为开发平台,对球头立铣刀端刃前刀面的刃磨过程进行仿真.建立了一套铣刀端刃前刀面的虚拟加工系统,通过刃磨参数优化,可实现端刃前刀面与周刃前刀面的光滑连接和良好的"S"刃形.模拟仿真发现端刃前刀面有一个很窄的刃带,分析了砂轮姿态对刃带宽度的影响.     

球面铣刀制造中的数学模型研究

介绍了球面铣刀成形原理、刃口曲线求解模型、刃口曲线相关参数的优化模型、磨制后刀面的机构和相应数学模型，并用实例验证上述模型的可靠性，最后还讨论了砂轮磨损对刃口曲线的影响。为球面铣刀的国产化提供了参考。     

球头刀铣削过程动力学模型

建立了考虑刀杆柔性的球头铣刀铣削振动模型,探讨了交变轴向力对刀杆固有频率的影响。考虑刀具动态变形和工件表面波纹对切削厚度的再生反馈,建立了球头刀铣削动力学模型,对铣削中的动态铣削力和刀杆振动进行了仿真,证明了离线仿真可以对铣削过程动特性做出预测。     

轴向车铣理论切削力的研究

以瞬时切削面积为主要研究对象建立了瞬时切削力的计算模型,并对瞬时切削力的变化进行了仿真。结果表明,轴向车铣为多参数影响下的变切削力加工,单齿瞬时切削力在整个切削过程中都是一个变化量,且圆周刃为主切削刃,其切削力远大于端面刃。在一次完整的切削过程中,整个刀齿的瞬时切削力产生两次突变。     

考虑刀具变形的球头铣刀铣削力建模与仿真

提出了准确识别参与切削的切削刃段的实体造型方法；基于铣削力与切削负载之间的经验关系，建立了三分量的球头铣刀铣削力模型；通过将刀具简化为一个悬臂梁结构，给出了刀具变形计算公式；从刀具变形对刀齿切削路径影响的几何关系出发，推导了三维进给运动下的瞬时切厚表达式。在此基础上，开发了完整的球头铣刀三轴铣削过程铣削力仿真系统。仿真计算和试验结果表明了模型及算法的正确性。     

基于线性插补加工零刃带螺旋回转面刀具的精度研究

针对多轴线性插补方法加工零刃带回转面刀具建立了刃带宽度误差的分析模型,兼顾分析了两个几何体——砂轮大圆和锥面,在工件表面按一定规律运动时对刀刃宽度的精度影响,给出了减小误差的方法。同时提出了刀刃节点交错的刀位(CL)轨迹计算原理,可以大大改善刀具加工工件的表面质量,此方法简单可靠,具有通用性。     

CUTTING TEMPERATURE MODELING BASED ON NON-UNIFORM HEAT INTENSITY AND PARTITION RATIO

ABSTRACT

The understanding of temperature distribution along the tool-chip interface is important for machining process planning and tool design. Among many temperature modeling studies, uniform heat partition ratio and/or uniform heat intensity along the interface are frequently assumed. This assumption is not true in actual machining and can lead to ill-estimated results at the presence of sticking and sliding. This paper presents a new analytical cutting temperature modeling approach that considers the combined effect of the primary and the secondary heat sources and solves the temperature rise along the tool-chip interface based on the non-uniform heat partition ratio and non-uniform heat intensity along the interface. For the chip side, the effect of the primary shear zone is modeled as a uniform moving oblique band heat source, while that of the secondary shear zone is modeled as a non-uniform moving band heat source within a semi-infinite medium. For the tool side, the effect of the secondary heat source is modeled as a non-uniform static rectangular heat source within a semi-infinite medium; and the primary heat source affects the temperature distribution on the tool side indirectly by affecting the heat partition ratio along the interface. Imaginary heat sources are considered as a result of the adiabatic boundary condition involved along the tool-chip interface and of the insulated boundary conditions along both the chip back side and the tool flank face. The temperature matching condition along the tool-chip interface leads to the solution of distributed heat partition ratio by solving a set of linear equations. The proposed model is verified based on the published experimental data of the conventional turning process and it shows both satisfactory accuracy and improved match.     

CUTTING TEMPERATURE MODELING BASED ON NON-UNIFORM HEAT INTENSITY AND PARTITION RATIO

The understanding of temperature distribution along the tool-chip interface is important for machining process planning and tool design. Among many temperature modeling studies, uniform heat partition ratio and/or uniform heat intensity along the interface are frequently assumed. This assumption is not true in actual machining and can lead to ill-estimated results at the presence of sticking and sliding. This paper presents a new analytical cutting temperature modeling approach that considers the combined effect of the primary and the secondary heat sources and solves the temperature rise along the tool-chip interface based on the non-uniform heat partition ratio and non-uniform heat intensity along the interface. For the chip side, the effect of the primary shear zone is modeled as a uniform moving oblique band heat source, while that of the secondary shear zone is modeled as a non-uniform moving band heat source within a semi-infinite medium. For the tool side, the effect of the secondary heat source is modeled as a non-uniform static rectangular heat source within a semi-infinite medium; and the primary heat source affects the temperature distribution on the tool side indirectly by affecting the heat partition ratio along the interface. Imaginary heat sources are considered as a result of the adiabatic boundary condition involved along the tool-chip interface and of the insulated boundary conditions along both the chip back side and the tool flank face. The temperature matching condition along the tool-chip interface leads to the solution of distributed heat partition ratio by solving a set of linear equations. The proposed model is verified based on the published experimental data of the conventional turning process and it shows both satisfactory accuracy and improved match.     

复杂曲面五坐标加工中主曲率匹配法的刃形误差

主曲率匹配法是精密加工中一种较先进的算法,但在应用到圆环面刀具上时做了一些简化。对其中切削刃的简化所带来的误差进行了研究,建立了圆环面刀实际切削刃的数学表达式,提出了刃形误差的概念,推导出了误差表达式,并对若干关键参数的影响进行了定量研究。分析指出刃形误差是一种宽带误差,它对最大允许加工带宽有一定的限制,在实际应用主曲率匹配法时必须进行校验才能保证加工精度。     

基于遗传算法的超精密切削表面粗糙度预测模型参数辨识及切削用量优化

建立易于分析各切削用量对粗糙度影响关系的表面粗糙度预测模型和最优的切削用量组合,是超精密切削加工技术的不断发展的需要。针对最小二乘法和传统优化方法的不足,提出了将遗传算法用于超精密切削表面粗糙度预测模型的参数辨识,并用于求解最优切削用量,给出了金刚石刀具超精密切削铝合金的表面粗糙度预测数学模型和切削用量优化结果,进行了遗传算法和常规优化算法的比较,结果表明遗传算法较最小二乘法和传统的优化方法更适合于粗糙度预测模型的参数辨识及保证切削用量的最优。