基于有限元分析的飞刀优化设计及安全校核

汽车同步器齿套的滑块槽属难加工内表面。介绍了滑块槽加工工艺的国内外现状和加工原理,建立了切削滑块槽飞刀的数学模型,设计了加工齿套滑块槽部位的刀具。经过强度和刚度分析,证明刚度问题为首要校核目标。通过优化设计得到基于等刚度原理的飞刀结构,实践检验证明该刀具是适用的。     

汽车同步器齿套飞刀切削数学模型的建立及其试验验证

为了解决汽车同步器齿套滑块槽的表面加工问题,论文应用飞刀切削的原理提出了用复轨迹法加工汽车同步器齿套滑块槽的思想。通过对经典切削力指数模型进行变形,建立了一种包含切削前角新的切削力模型。设计了测量飞刀切削力试验。为判定模型中的各系数,用多元线性回归的方法处理试验数据,确定了切削力模型中的系数,得出了飞刀切削滑块槽的切削力数学模型。     

汽车变速箱同步器齿套滑块槽表面飞刀切削数学模型的建立

为了解决汽车同步器齿套滑块槽的表面加工问题,应用飞刀切削的原理,并提出了采用复轨迹法加工汽车同步器齿套滑块槽的思想.通过对经典切削力指数模型进行变形,建立了一种包含切削前角新的切削力模型.设计了测量飞刀切削力试验.为判定模型中的各系数,用多元线性回归的方法处理试验数据,确定了切削力模型中的系数,得出了飞刀切削滑块槽的切削力数学模型.     

飞刀加工汽车同步器齿套滑块槽的切削稳定性研究

简要介绍飞刀加工汽车同步器齿套滑块槽时存在的弊病,分析了导致切削颤振的原因.测量了飞刀加工时的主切削力,并以此建立其数学模型;通过改变进给量及切削速度的方法改着了切削振动,提高了生产质量和生产效率.     

汽车同步器齿套摆线加工数控机床结构总体方案设计

将传统的汽车同步器齿套倒锥及滑块槽的几种加工方法，与用摆线逼近法加工汽车同步器齿套倒锥及滑块槽的加工方法加以比较，阐明了这种新方法产生的背景和优势；介绍了用摆线加工滑块槽的原理；在此基础上设计了汽车同步器齿套摆线加工数控机床的总体结构；给出了机床的主要动力和运动参数，最后展望了这种方法的应用前景。     

滑动齿套拨叉槽的立方氮化硼刀具切削工艺试验研究

为了确定硬态切削代替磨削加工滑动齿套拨叉槽时各参数对其表面质量的影响,采用立方氮化硼刀具对20CrMnTi棒料进行切削,利用正交试验法对加工表面粗糙度进行了直观分析和方差分析,得出切削速度、进给量、背吃刀量对拨叉槽表面粗糙度的影响规律,并给出拨叉槽加工时合理的切削用量;同时也对加工过程中刀具的磨损进行分析,为滑动齿套拨叉槽的立方氮化硼切削工艺参数的选取提供了依据。     

直齿锥齿轮摆线旋分加工数学模型及参数优化（英文）

针对直齿锥齿轮加工方法间歇分度、生产效率低的问题,基于直齿锥齿轮摆线旋分加工方法,采用空间曲线逼近直线的数学方法解释直齿锥齿轮旋分加工原理。在此基础之上,给出摆线旋分加工数学模型,即切削点轨迹的数学模型,并分析影响参数,确定各参数范围及影响规律,进而获得符合加工要求的切削点轨迹。     

直齿锥齿轮摆线旋分加工数学模型及参数优化

针对直齿锥齿轮加工方法间歇分度、生产效率低的问题，基于直齿锥齿轮摆线旋分加工方法，采用空间曲线逼近直线的数学方法解释直齿锥齿轮旋分加工原理。在此基础之上，给出摆线旋分加工数学模型，即切削点轨迹的数学模型，并分析影响参数，确定各参数范围及影响规律，进而获得符合加工要求的切削点轨迹。     

基于有限元分析的汽车同步器齿套倒锥刀具安全校核

为了解决汽车同步器齿套的倒锥部分的表面加工问题,本文在分析传统加工缺陷的基础上,针对专用的摆线数控机床,从功能和结构上设计了加工倒锥部位的刀具.通过有限元对其进行强度、刚度及动力学模态的分析,并进行了安全校核.理论和实践证明该刀具是适用的.     

旋分新概念加工机床在中国申请专利

德国维拉(WERA)公司和南京第二机床厂合作生产的旋分新概念加工机床已在中国申请专利。该机的应用范围极广，被汽车行业及工具行业大量采用，其特点如下：(1)机床采用旋分加工原理，刀具主轴与工件主轴之间的运动关系通过专用软件构成复杂的函数关系，使机床具有很高的柔性，借助于刀具系统设计，以包络曲线来拟合被加工工件形面，完成不同形状的工件加工。加工范围包括R系列沟槽类(小轴、盘齿、轴齿)，M系列型面(四方、六方、多边、结合齿)。(2)机床工件主轴及刀具主轴转速极高，可获得极高的切削速度，适合采用硬质合金刀具进行干式切…     

Development of an on-line tool-life monitoring system using acoustic emission signals in gear shaping

Sensing techniques for monitoring machining processes have been one of the focuses of research on process automation. This paper presents the development of on-line tool-life monitoring system for gear shaping that uses acoustic emission (AE). Characteristics of the AE signals are related to the cutting condition, tool material and tool geometry in the cutting of metals. The relationship between AE signal and tool wear was investigated experimentally. Experiments were carried out on the gear shaping of SCM 420 material with a pinion cutter having 44 teeth. Root-mean-square (RMS) AE voltages increase regularly according to tool wear. It is suggested that the maximum value of RMS AE voltage is an effective parameter to monitor tool life. In this study, not only the acquisition method of AE signals for rotating objects but also the signal-processing technique were developed in order to realize the in-process monitoring system for gear shaping. The on-line tool-life monitoring system developed has been successfully applied to gear machining processes.     

用球头铣刀加工模具曲面时刀具路径的优化

以球头铣刀产生平行走刀精加工刀具路径为例,从行距、步长、曲面分区加工、切入切出点确定、行间和层间附加圆滑转接等方面对刀具路径的优化进行研究,指出行距和步长的选择应综合考虑,以兼顾生产效率和曲面质量。当曲面曲率半径变化较大时,应分区确定行距和步长。切入切出点以及刀路间圆滑过渡不仅能避免刀具过早失效,且能提高模具表面质量。     

Cutting force model for machining of CFRP laminatewith diamond abrasive cutter

The article presents a cutting force model for trimming operations of CFRP laminate with diamond abrasive cutters. Those tools are more and more encountered on industrial applications of CFRP trimming, due to their abrasion resistance and their low cost. Contrary to endmills, they consist of a large number of cutting grits, randomly distributed around the tool. To tackle the issue, a continuous model of tool engagement is proposed. Validity of the approach is verified. A mechanical model of cutting forces, adapted to CFRP laminate, is then presented. The evolution of specific cutting coefficient in relation to fibres orientation is investigated through a piecewise constant model. It leads to the proposal of a sine model for the specific cutting coefficients. The simulated forces are in good agreement with the experimental results of cutting tests, carried out in multidirectional CFRP laminate for different fibres orientation and widths of cut. Cutting mechanisms are finally discussed depending on fibres orientation.     

电镀金刚石圆柱铣刀在数控石材加工中磨损实验研究

本文采用正交实验方法,对电镀金刚石涂层刀具在数控石材加工中进行试验,研究加工参数和金刚石颗粒性能对电镀金刚石刀具磨损量的影响,并利用体式显微镜对磨损后的刀具表面形貌进行了分析.试验结果表明:影响金刚石铣刀磨损量的主要因素是金刚石粒度,加工参数中影响较大的是径向切深,其次是主轴转速,进给速度影响较小.刀具底面的磨损比侧面严重,刀具底面的磨损形式主要是犁沟,金刚石主要以脱落为主;侧面的磨损形式主要是磨平,金刚石颗粒以破碎为主.     

Mechanistic modeling of five-axis machining with a general end mill considering cutter runout

The accurate and fast prediction of cutting forces in five-axis milling of free-form surfaces remains a challenge due to difficulties in determining the varying cutter-workpiece engagement (CWE) boundaries and the instantaneous uncut chip thickness (IUCT) along the tool path. This paper proposes an approach to predict the cutting forces in five-axis milling process with a general end mill considering the cutter runout effect that is inevitable in the practical machining operations. Based on the analytical model of cutting edge combined with runout parameters, the expression of the rotary surface formed by each cutting edge undergoing general spatial motion is firstly derived. Then by extracting the feasible contact arc along the tool axis, a new arc-surface intersection method is developed to determine the CWE boundaries fast and precisely. Next, the circular tooth trajectory (CTT) model is developed for the calculation of the IUCT with a slight sacrifice of accuracy. In comparison with the true IUCT calculated by the trochoidal tooth trajectory model, the approximation error introduced by the circular assumption is negligible while the computational efficiency improves a lot. Finally, combining with the calibrated cutting coefficients and runout parameters, comprehensive formulation of the cutting force system is set up. Simulations and experimental validations of a five-axis flank milling process show that the novel CTT model possesses obvious advantages in computing efficiency and accuracy over the existing approaches. Rough machining of a turbo impeller is further carried out to test the practicability and effectiveness of the proposed mechanistic model.     

可拆卸式浮动切刀在修边模具中的应用

分析了现有废料切断结构存在的问题及其产生的原因,并针对其弊端提出了一种可拆卸式浮动切刀结构。介绍了可拆卸式浮动切刀的组成、冲裁力的计算、行程和工作过程。该结构不仅提高了产品的表面质量,而且拆卸方便,冲压稳定,极大地提高了工作效率。     

A cutter tool monitoring in machining process using Hilbert–Huang transform

This paper presents the use of accelerometer signals in order to detect cutter tool wear and tool fault under different cutting conditions. The new method, Hilbert–Huang transform (HHT), was applied to the cutter tool wear and tool fault monitoring and compared to Fourier transform. In the results processed by short-time Fourier transform the cutter tool wear or tool fault is detected by increasing the power in the power spectral density.The acceleration signals (processed by using HHT) change the frequency in the marginal spectra as a result of geometric change of the cutter tool. Results are presented in both frequency domain and time–frequency domain in the case of HHT. The HHT presents data locally without harmonics. This fact permits overcoming of the nonlinearity and nonstationarity of the acceleration signal. Axes x and z are the most sensitive to both HHT and Fourier transform.     

小松压力机偏心齿轮的加工技术

文章分析了小松压力机的偏心齿轮加工技术,制定了小空刀槽人字齿轮的切齿工艺方案,对保证偏心同相位进行了理论分析与计算,给出了合适的加工和检测方法.通过切削试验,确定了合理的工艺参数.     

A novel hob cutter design for the manufacture of spur-typed cutters

Spur-typed cutters with multiple cutting angles are important tools frequently used in the manufacture of many machine elements. Due to their complex geometry, the production of these cutters involves milling and several grinding processes. Such a complex manufacturing process, coupled with the need for expensive manufacturing tools, makes the cutters costly.Undercutting is a phenomenon that causes weakness at the root of a gear. Engineers use shifted gears, modified tooth profiles, or changes in the pressure angle to overcome undercutting in gears. However, in this paper, by utilizing the undercutting phenomenon, a novel design of straight-sided hob cutter with multiple pressure angles is proposed for the manufacture of spur-typed cutters. With the simultaneous application of multiple pressure angles, this tool design concept significantly simplifies the manufacturing process. The effects of cutting angles, the degree of undercutting, and the width of the top land of the cutter are studied. The concepts and results proposed in this paper are beneficial as design guidance for tool designers and manufacturers.