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以微径球头铣刀铣削力为研究对象,分析了刀具刃线模型.将刀具沿刀轴方向离散为若干切削单元,分别依照单齿切削及两齿切削求得各切削单元的实际瞬时切削厚度.基于实体造型的方法提取了参与切削的切削刃段,并通过实验识别了瞬时切削力系数及主轴径向跳动参数,建立了综合考虑主轴径向跳动、微细铣削所特有的尺度效应的影响及可能出现的单齿切削现象的微径球头铣刀铣削力模型.实验结果验证了所提模型的有效性和可行性. 相似文献
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《机械科学与技术》2017,(4):586-591
采用双锋角钻头对碳纤维复合材料进行钻削试验,基于反向传播算法的人工神经网络建立钻削轴向力与主轴转速、进给速度之间的非线性关系模型,对比分析三种不同第二主切削刃与第一主切削刃之比的双锋角钻头在试验加工参数下钻削轴向力变化规律。结果表明:与多元线性回归预测模型对比,在相同试验数据为基础的预测计算下,BP神经网络预测值相对误差明显减小,网络预测值误差均在3%之内,而多元线性回归模型最大误差值达到了12.46%,BP神经网络能建立更精准轴向力预测模型。从降低钻削轴向力的角度分析,应采用第二主切削刃与第一主切削刃之比为1的双锋角钻头进行钻削加工。 相似文献
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钛合金旋转超声辅助钻削的钻削力和切屑研究 总被引:1,自引:0,他引:1
针对难加工材料钛合金在采用普通麻花钻传统钻削过程中存在钻削力和扭矩较大使得钻孔困难,刀具使用寿命低,连续长切屑易缠绕刀具、划伤孔加工表面、增大刀具-切屑-工件孔壁之间的摩擦以及排屑差引起堵屑和卡刀具的问题,引入一种新刃型刀具(即八面钻),并结合超声振动钻削技术,进行了钛合金旋转超声辅助钻削试验。分析了旋转超声辅助钻削和普通钻削中切屑形成原理,采用文中所设计的旋转超声振动钻削主轴结合BV100立式加工中心平台、测力系统和非接触激光测量系统进行了无冷却条件下基于八面钻的钛合金旋转超声辅助钻削和普通钻削试验以及钻削力、扭矩和切屑形态的研究。试验结果表明:相比于普通钻削,超声钻削明显降低钻削力和扭矩分别为19.07%~20.09%和31.66%~34.3%,明显增强了钻头横刃和主切削刃的切削能力,获得了良好的断屑和排屑效果,提高了切削过程的稳定性,能够极大改善钛合金钻孔过程钻削困难、刀具使用寿命低和孔加工质量差的问题。 相似文献
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以螺旋铣孔工艺时域解析切削力建模、时域与频域切削过程动力学建模、切削颤振及切削稳定性建模为基础,研究了螺旋铣孔的切削参数工艺规划模型和方法。切削力模型同时考虑了刀具周向进给和轴向进给,沿刀具螺旋进给方向综合了侧刃和底刃的瞬时受力特性;动力学模型中同时包含了主轴自转和螺旋进给两种周期对系统动力学特性的影响,并分别建立了轴向切削稳定域和径向切削稳定域的预测模型,求解了相关工艺条件下的切削稳定域叶瓣图。在切削力和动力学模型基础之上,研究了包括轴向切削深度、径向切削深度、主轴转速、周向进给率、轴向进给率等切削工艺参数的多目标工艺参数规划方法。最后通过试验对所规划的工艺参数进行了验证,试验过程中未出现颤振现象,表面粗糙度、圆度、圆柱度可以达到镗孔工艺的加工精度。 相似文献
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《机械制造与自动化》2017,(4):105-109
针对航空航天制造使用的碳纤维复合材料和钛合金叠层结构材料的特殊特性,将钻头主切削刃离散成许多个微元,把切削过程简化为微元的斜角切削,采用数学分析和经验结合的方法,建立标准麻花钻的钻削力预测模型,运用Matlab/Simulink进行钻削力仿真,将仿真结果和试验结果进行比较和验证,结果表明钻削力模型符合实际情况。将得到的钻削力预测模型应用到钻削叠层结构中,得到一种钻削叠层结构的钻削力预测模型。 相似文献
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在钻削加工中,钻头主切削刃的跳动量直接影响加工孔的精度与要求.就钻头主切削刃的跳动、刃口修磨与测量作了分析并介绍了解决的方法. 相似文献
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微铣削中考虑刀具跳动的瞬时切厚解析计算方法 总被引:2,自引:1,他引:2
通过研究刀具实际切削过程中的余摆线轨迹及其影响,提出一种新的瞬时切厚解析计算方法,并针对两齿、四齿的情况给出瞬时切厚的具体计算公式。在两齿和四齿铣槽工况下,分析刀具跳动量和跳动角度对各齿切削过程的影响。该方法考虑刀具的综合径向跳动(包括主轴跳动,刀具制造安装误差等综合形成的径向跳动值),适用于微铣削中任意齿数刀具瞬时切厚的计算。通过与宏观铣削中的传统切厚计算公式、BAO模型和Newton-Raphson等数值法对比,量化指出了微细铣削加工与传统宏观铣削加工的一些不同,同时验证了提出的方法具有计算简洁、精度高和通用性强的优势。基于该模型进行了微铣削铣槽试验中切削力的预测,预测结果和试验结果相符良好,验证了模型的正确性和实用意义。 相似文献
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在难加工材料高锰钢钻削过程中,刀具破损严重,通过试验研究发现,改进刀具切削刃的形状,可以提高刀具寿命,提高生产率。利用8901F数字三相电参数测量仪测量钻削功率,结果表明改进的刃形在高锰钢钻削过程中钻削功率明显降低。 相似文献
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Wanqun Chen Xiangyu Teng Dehong Huo Quanlong Wang 《The International Journal of Advanced Manufacturing Technology》2017,93(9-12):3005-3016
Micro milling, as a versatile micro machining process, is kinematically similar to conventional milling; however, it is significantly different from conventional milling with respect to chip formation mechanisms and uncut chip thickness modelling, due to the comparable size of the edge radius to the chip thickness, and the small per-tooth feeding. Considering tool runout and dynamic displacement between the tool and the workpiece, the contour of the workpiece left by previous tool paths is typically in a wavy form, and the wavy surface provides a feedback mechanism to cutting force generation because the instantaneous uncut chip thickness changes with both the vibration during the current tool path and the surface left by the previous tool paths. In this study, a more accurate uncut chip thickness model was established including the precise trochoidal trajectory of the cutting edge, tool runout and dynamic modulation caused by the machine tool system vibration. The dynamic regenerative effect is taken into account by considering the influence of all the previous cutting trajectories using numerical iteration; thus, the multiple time delays (MTD) are considered in this model. It is found that transient separation of the tool-workpiece occurring at a low feed per tooth, caused by MTD and the existing cutting force models, is no longer applicable when transient tool-workpiece separation occurs. Based on the proposed uncut chip thickness model, an improved cutting force model of micro milling is developed by full consideration of the ploughing effect and elastic recovery of the workpiece material. The proposed cutting force model is verified by micro end milling experiments, and the results show that the proposed model is capable of producing more accurate cutting force prediction than other existing models, particularly at small feed per tooth. 相似文献
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The cutting force prediction is essential to optimize the process parameters of machining such as feed rate optimization, etc. Due to the significant influences of the runout effect on cutting force variation in milling process, it is necessary to incorporate the cutter runout parameters into the prediction model of cutting forces. However, the determination of cutter runout parameters is still a challenge task until now. In this paper, cutting process geometry models, such as uncut chip thickness and pitch angle, are established based on the true trajectory of the cutting edge considering the cutter runout effect. A new algorithm is then presented to compute the cutter runout parameters for flat-end mill utilizing the sampled data of cutting forces and derived process geometry parameters. Further, three-axis and five-axis milling experiments were conducted on a machining centre, and resulting cutting forces were sampled by a three-component dynamometer. After computing the corresponding cutter runout parameters, cutter forces are simulated embracing the cutter runout parameters obtained from the proposed algorithm. The predicted cutting forces show good agreements with the sampled data both in magnitude and shape, which validates the feasibility and effectivity of the proposed new algorithm of determining cutter runout parameters and the new way to accurately predict cutting forces. The proposed method for computing the cutter runout parameters provides the significant references for the cutting force prediction in the cutting process. 相似文献
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A theoretical cutting force model for helical end milling with cutter runout is developed using a predictive machining theory, which predicts cutting forces from the input data of workpiece material properties, tool geometry and cutting conditions. In the model, a helical end milling cutter is discretized into a number of slices along the cutter axis to account for the helix angle effect. The cutting action for a tooth segment in the first slice is modelled as oblique cutting with end cutting edge effect and tool nose radius effect, whereas the cutting actions of other slices are modelled as oblique cutting without end cutting edge effect and tool nose radius effect. The influence of cutter runout on chip load is considered based on the true tooth trajectories. The total cutting force is the sum of the forces at all the cutting slices of the cutter. The model is verified with experimental milling tests. 相似文献
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Guifeng Wang Huiyue Dong Yingjie Guo Yinglin Ke 《The International Journal of Advanced Manufacturing Technology》2016,82(1-4):179-195
In this paper, a new approach based on industrial robotic boring is proposed to solve problems associated with intersection holes during aircraft assembly. A model is established to predict the dynamic cutting force of a robotic machining system. The robot stiffness coupling, chip deformation, and plowing interference affecting the cutting force are considered using the principles of cutting mechanics and the Oxley orthogonal cutting model. By solving a numerical solution of motion differential equation, the cutting force components in the radial, tangential, and feed directions are obtained by the model. In addition, an advanced curve intersection method is developed to identify the instantaneous uncut chip area and cutting edge contact length. Verification tests were performed on an ABB-IRB6600-175/2.55 robot for titanium alloy TC4 to determine the accuracy of the predictions. The results show that the simulated and measured cutting forces were in good agreement under different cutting conditions. By analyzing simulated and experimental results, we show that the model can be applied to predict the occurrence of vibration and has application value in terms of suppressing vibration during robotic boring. 相似文献
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Particleboard is a wood based composite extensively used in wood working. Drilling is the most commonly used machining process in furniture industries. The surface characteristics and the damage free drilling are significantly influenced by the machining parameters. The thrust force developed during drilling play a major role in gaining the surface quality and minimizing the delamination tendency. The objective of this study is to measure and analyze the cutting conditions which influences the thrust force in drilling of particle board panels. The parameters considered are spindle speed, feed rate and point angle. The drilling experiments are performed based on Taguchi’s design of experiments and a response surface methodology (RSM) based mathematical model is developed to predict the influence of cutting parameters on thrust force. The results showed that high spindle speed with low feed rate combination minimizes the thrust force in drilling of pre-laminated particle board (PB) panels. 相似文献
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Qiang Guo Bo Zhao MingYang Zhang Yan Jiang Yan Zhang 《The International Journal of Advanced Manufacturing Technology》2017,93(5-8):1737-1749
Classical ways of computing cutting force coefficients cannot be used by the cutters with non-uniform helix and pitch angles. So, this paper presents a novel separate-edge-forecast method to compute cutting force coefficients for any kind of flank-end cutter, especially for cutters with non-uniform helix and pitch angles. Using this method, the cutter runout can be combined into the cutting force coefficients without computing the cutter runout parameters. Simultaneously, the method predicts the cutting force coefficients for every cutter edge. Firstly, a series of three-axis machining experiments, which must satisfy the specific condition that only one cutter edge is removing materials at any time, is conducted. Then, the cutting force-curves are divided into N force lobes. Each lobe is assigned to the corresponding cutter edge using an algorithm. Subsequently, the cutter edge and the corresponding cutting force lobe are used to determine the cutting force coefficients. This means N cutter edges have N groups of cutting force coefficients, correspondingly. Finally, in order to verify the validity and correctness of the proposed method, a cutter with non-uniform helix and pitch angle is utilized to predict cutting force coefficients based on which the cutting forces are also computed. The results demonstrate that the cutting forces predicted agree well with the data measured. Simultaneously, it can be observed that the method can predict the coefficients considering the cutter runout effect. 相似文献
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基于离散元的模拟月岩切削负载特性数值模拟及试验验证 总被引:1,自引:1,他引:0
钻取采样是人类获取月球岩石类样品的重要手段,钻进负载的稳定性是确保月岩采样任务成功的关键因素。由于岩石属性直接决定其可钻性等级,并影响钻进负载,有必要在地面环境中,分析岩石本构模型与钻进负载之间的关系,构建不同可钻性等级的岩石样本模型,开展模拟钻进试验,获知不同钻进参数下岩石采样的钻进载荷变化情况。据此,将地面条件下大理岩样本选作模拟月岩切削特性的研究对象,基于二维颗粒流程序(Particle flow code 2 dimensions,PFC2D),建立小切削深度下仿真分析模型。利用Plackett-Burman试验(PB试验)和中心组合设计(Central composite design,CCD)方法,确定影响岩石切削特性的微观参数,开展不同切削深度下的模拟月岩切削负载试验验证。经仿真分析与试验验证能得到与岩石切削特性相对应的离散元模型,试验结果表明该仿真模型在较小切削深度条件下的切削负载变化规律与实际情况一致。通过研究获得了一种建立模拟月岩离散元切削模型的建模方法,为后续分析钻头/切削刃构型参数对钻进/切削负载的影响提供了研究条件。 相似文献