低能耗变频振动下料计算机测控系统的研究

金属棒料的精密下料问题广泛存在于工业实际中,针对低能耗变频振动下料方法的特点,提出为了实现可靠、稳定和自动下料的目标,必须建立一个计算机测控系统.围绕计算机构建了测控系统的硬件结构,根据低能耗变频振动下料方法的特点开发了基于虚拟仪器LabVIEW的软件平台和人机交互界面.基于计算机测控系统实现了对LY8、20#钢和45#钢棒料的稳定下料,实验结果表明,下料效果非常理想.计算机测控系统的成功研发为进一步研究低能耗变频振动下料方法的机理奠定了坚实基础.     

基于坯料重量的板簧优化下料系统方案设计

针对提高板簧下料工序材料利用率的问题,提出一种基于簧坯坯料重量的板簧优化下料系统设计方案,详细阐述了板簧优化下料原理、下料系统方案构成、系统关键技术组成.通过该方案的实施,对提高板簧下料时的材料利用率、降低生产成本具有一定的实用意义.     

下料时初始激振频率的选择方法

针对金属棒料的精密下料问题,采用断裂力学和材料力学相结合的方法,获得棒料下料时临界最大初始激振频率和最小激振频率的计算公式.分析不同材质棒料下料时初始激振频率的选择方法.45钢棒料的下料实验结果表明,该公式所得的结果和下料实验结果相吻合.     

计算机程相贯件下料中的应用

介绍一种对于相贯件的计算机下料方法,文中给出了程序设计框图,该方法具有快速、准确、修改方便的特点.     

新型变频振动精密下料方法的振动测控研究

新型变频振动精密下料方法利用变频振动实现低应力下料,关键是建立有效的振动测控系统.在分析了下料系统原理的基础上,构建了振动测控系统的硬件结构.采用压电加速度传感器配合电荷放大器,通过数据采集卡对精密下料系统的振动进行采样,基于虚拟仪器的振动测控系统实现对下料机的各种测控,界面友好,实用性强.通过对精密下料机振动的成功测控实现了对硬铝棒料的精密下料,实验结果表明:应用振动测控系统时的下料效果非常理想,可以投入使用.     

热锻下料模具的改进

对于φ28～φ30mm的小直径棒料可以冷下料也可以热下料,而对于φ50～φ60mm以上的棒料,为了降低设备吨位,提高下料模具的寿命,一般普遍采用先加热,然后再截成一个个小料段的方法。热下料模具经常见到的形式有开式剪切模具、半封闭剪切模具和全封闭剪切模具。开式剪切模具结构简单,主要是一个模座套筒和一个模柄刀板,但截下的棒料的端头压塌严重,剪切后坯料的端头出现了明显偏斜,不     

一维下料问题的优化算法及其编程

提出了一种下料方案的算法,结合Kantorovich建立的线性规划模型,给出适合一维下料问题的数学模型.设计了一种求最优解的算法,并对最优解进行了分析.利用计算机编程完整地实现了一维下料问题的优化,解决生产中广泛存在的一维下料问题.     

箱形中梁下料工艺

根据巴基斯坦平车箱形中梁的结构特点及主要技术要求,分析其中梁腹板、中梁下盖板的工艺特性,制定出合理的下料工艺方案.     

利用Excel实现最省下料工艺

针对机械加工中最省下料问题,运用线性规划理论,建立数学模型。介绍运用Excel的“规划求解”功能解决最省下料问题的方法。该方法具有方便实用、简单快捷等优点,对工程技术人员有实用价值。     

利用计算机进行优化下料

生产中常要求随时按照生产计划对进库原材料迅速进行优化套裁，提高材料的下料利用率。本文介绍的利用计算机代化下料方法，已在AST—386计算机上运行通过，经使用效果良好。一、优化下料的数学过程优化下料的基本数学过程是子代化→线性规划→整数规划，以此得到最优整数解。1．子优化过程设参与套我下料的零件有M种，则会有K=2M－1之多的零件组合方式，每一种组合方式又可有多个下料模式。对这些下料模式，要进行于优化，即首先通过设定一个下料分料要求，在众多的下料模式中优化出一批下料余量符合要求的下料模式。以己种零件下料为例…     

金属切削过程中切削热和切削温度场的仿真分析

切削热的产生和由它导致的切削温度是影响金属切削状态的重要物理因素之一。笔者通过45#圆钢在几种不同切削速度下的温度场的仿真分析,直观的表现出切削速度对金属切削热的影响,从而对优化切削参数和研究刀具磨损机理提供方法依据。     

Modeling and experimental verification of cutting forces in gear tooth cutting

Due to complex cutting edge profile of an involute cutter, calculations of chip width and consequently cutting force are quite problematical. This article presents a mechanistic approach in the prediction of cutting force components arising in the course of gear tooth cutting by an involute form cutter. To permit calculation of chip width (and so cutting forces), a discrete model is utilized and cutting force components are then derived using Kienzle approach. Moreover, several experiments are performed under different cutting conditions to prove the effectiveness and accuracy of the used method. The results have revealed that cutting force components can be predicted in form gear tooth cutting with a significant accuracy.     

等离子弧加热切削时刀具材料和几何角度的研究

采用等离子弧加热切削加工超硬金属材料,通过对加热切削时刀具材料和刀具几何角度的试验研究,得出选择刀 具材料和几何角度的方法。     

Modeling of the minimum cutting thickness in micro cutting with consideration of the friction around the cutting zone

Friction modeling between the tool and the workpiece plays an important role in predicting the minimum cutting thickness during TC4 micro machining and finite element method (FEM) cutting simulation. In this study, a new three-region friction modeling is proposed to illustrate the material flow mechanism around the friction zone in micro cutting; estimate the stress distributions on the rake, edge, and clearance faces of the tool; and predict the stagnation point location and the minimum cutting thickness. The friction modeling is established by determining the distribution of normal and shear stress. Then, it is applied to calculate the stagnation point location on the edge face and predict the minimum cutting thickness. The stagnation point and the minimum cutting thickness are also observed and illustrated in the FEM simulation. Micro cutting experiments are conducted to validate the accuracy of the friction and the minimum cutting thickness modeling. Comparison results show that the proposed friction model illustrates the relationship between the normal and sheer stress on the tool surface, thereby validating the modeling method of the minimum cutting thickness in micro cutting.     

金属切削中如何选择切削液

概述了切削液的种类和性能,介绍了目前切削液的使用情况,重点探讨了在不同的材料、不同的切削方法、各种常见刀具及良好的经济效益下选择切削液的基本原则.     

基于共边切割方法的板材切割路径优化

常规的板材切割是切割完一个零件后再去切割另一个零件,如果两个零件的边有公共部分,则利用共边切割方法只进行一次切割就可以完成,这不但能提高切割效率而且还能节省切割成本.然而目前有关共边切割方法的研究还不太深入,共边切割方法对于切割路径的优化效果还没有完全发挥出来.提出了基于图论的"一笔画"共边切割方法和针对阵列矩形的"阶梯形"共边切割方法,并给出了实例.实例结果表明,提出的共边切割方法比现有的方法在割嘴和空行程和打孔点数上都有了很大的优化.     

“Peel cutting” – A new cutting method for difficult-to-cut workpieces with hard oxide surfaces

A new cutting method named “peel cutting” is proposed in this research to suppress notch wear in machining of metals with hard oxide surfaces. In general, metals are produced by hot deformation processes like rolling, forging, and extrusion, which cause hard oxide surfaces called scales on their surfaces. These hard scales need to be removed first in machining of precision parts. However, the machining causes the severe notch wear at the depth-of-cut position, where the tool contacts the hard scale. To solve this problem, the proposed peel cutting avoids this direct contact between the tool and the scale by inclining the end cutting edge at an extremely large inclination (oblique) angle. This extremely oblique cutting changes the material flow and generates a “burr-like chip”. In the proposed cutting method, the tool contacts only soft non-oxide metal under the scale during cutting. Cutting of titanium alloy Ti–6Al–4V is conducted by modifying commercial tools to provide extremely large inclination angles, and it is clarified that an inclination angle of 70 deg or greater is required to realize the proposed cutting. Tool wear in the proposed cutting of the alloy with a hard scale is also observed in comparison with the ordinary cutting, and the result verifies that the notch wear can be suppressed successfully by the proposed peel cutting.     

An experimental investigation of oblique cutting mechanics

In this study, an experimental investigation of oblique cutting process is presented for titanium alloy Ti-6Al-4V, AISI 4340, and Al 7075. Important process parameters such as shear angle, friction angle, shear stress, and chip flow angle are analyzed. Transformation of the data from the orthogonal cutting test results to oblique cutting process is applied, and the results are compared with actual oblique cutting tests. Effects of hone radius on cutting forces and flank contact length are also investigated. It is observed that the shear angle, friction angle, and shear stress in oblique cutting have the same trend with the ones obtained from the orthogonal cutting tests. The transformed oblique force coefficients from orthogonal tests have about 10% discrepancy in the feed and tangential directions. For the chip flow angle, the predictions based on kinematic and force balance results yield better results than Stabler's chip flow law. Finally, it is shown that the method of oblique transformation applied on the orthogonal cutting data yields more accurate results using the predicted chip flow angles compared to the ones obtained by the Stabler's rule.     

绿色切削的关键技术及应用

绿色制造是人类社会可持续发展的基础。是制造业未来的发展方向，实施绿色切削势在必行。干切削较之湿切削是一种创新的绿色制造工艺。分析了传统切削方式及其对外部系统的影响。研究了干切削的关键技术：刀具技术、机床技术、准干切削技术、绿色切削液技术及其应用。提出了实现绿色切削之措施。     

水下切割技术的研究

介绍目前已开发出的多种水下切割技术,如研料高压水射流法、金刚石串珠曲线锯法、旋转内割刀法等.通过比较几种主要的水下切割技术的特点,可在实施水下切割时选取适宜的切割技术.