圆形管截面全锥面翻领成型器及其数学模型研究

提出了全锥面翻领成型器的基本思想,分析了其优缺点,并对其数学模型进行了详细研究,包括领口交接曲线、肩曲面、边界曲线。在计算机上对所建模型进行了Pro/E三维仿真验证。为正确设计圆形管全锥面翻领成型器提供理论依据。     

无领翼式翻领制袋成型器的研究

研究了包装机械中最新使用的新型无领翼式翻领制袋成型器的数学模型,推导出其空间领口交接曲线以及平面展开领口交接曲线的数学模型,并得出了新型无领翼式翻领制袋成型器数学模型参数间的关系,为新型无领翼式翻领制袋成型器的生产制造研究提供了数学依据.     

圆形偏置翻领成型器的研究

研究了用于立式制袋-充填-封口机的圆形偏置翻领成型器.提出了用两个传统圆形截面翻领成型器进行组合的制作方法,并给出了圆形偏置翻领成型器的交接曲线及边界曲线方程,建立了数学模型.为圆形偏置翻领成型器的加工制作提供了理论依据.     

矩形管双焦点不对称翻领成型器曲面研究

研究了矩形管双焦点不对称翻领成型器领口交接曲线和曲面的形成,建立了矩形管双焦点不对称翻领成型器的肩曲面及其边界曲线的数学模型,给出了其高度与其它参数的关系式,为矩形管双焦点不对称翻领成型器的CAD/CAM提供了数学理论依据.     

翻领成型器曲面研究

研究了翻领成型器的交接曲线和曲面形成,给出了翻领成型器的肩曲面及其边界曲线的数学模型,指出左右对称的两肩曲面是两个顶点不同的锥面.此外,从几何角度提出了设计参数e的限制条件,为正确设计翻领成型器提供了依据.     

圆形料管翻领成型器曲面的成形过程研究

从一个新的视角研究了圆形料管翻领成型器的曲面的成型.由平张薄膜在翻领成型器外表面的运动特性,给出了流线的定义并建立了圆形料管翻领成型器的流线数学模型,以及在此基础上提出了影响翻领成型器曲面成形过程中的两个重要参数:和.然后运用Pro/Engineer软件,建立了圆形料管翻领成型器的曲面在成形过程中的任意状态下的三维曲面数字模型.     

基于MATLAB的翻领成型器领口曲线的展开及可视化

为使翻领成型器领口曲线的设计更精确、简便,并直观地反映出设计参数之间、设计参数与结果之间的关系及设计效果.根据翻领成型器领口曲线的数学模型,介绍利用MATLAB编程作展开的方法,并对中间待选参数的数据关系、展开曲线的平面图形及领口曲线的立体图形作可视化处理并予以直接显示.结果表明,MATLAB为翻领成型器领口曲线的展开设计及加工提供了快捷有效的途径,同时也为MATLAB用于包装机械的设计提供了一个很好的范例.     

正八边形立管截面翻领成型器设计方法

研究了正八边形翻领成型器的领口交接折线和边界折线的形成,从理论上建立了以直线代替曲线,使翻领曲面转化为平面的以直代曲的设计方法,并推导了正八边形翻领成型器的数学模型,给正八边形翻领成型器的CAD/CAM制造及手工制作提供了理论依据。     

翻领成型器领口曲线的程序计算展开法

根据翻领成型器领口曲线的数学模型，介绍一种利用计算器复杂公式存贮的特殊功能，预编程序计算相关参数。然后画领口曲线展开图的方法。     

翻领成型器计算机辅助设计

介绍了根据翻领成型器的数学模型,在计算机上进行三维模型设计的方法.主要介绍了如何用Pro/ENGINGEERING软件,根据翻领成型器的参数来生成曲线、曲面最后到三维实体模型的技术过程.     

Modelling the Material Flow and Web Tension in the Vertical Form–Fill–Seal Packaging Process

Vertical form–fill–seal (VFFS) machines are widely used to form bags for packaging products such as confectionary and snack food. One critical component of the machine is the forming shoulder, which needs to manipulate, without damage, the packaging material from a flat state into a tube. Some models of the geometry of the shoulder are available and have been used to help with its design and manufacture. However, there currently exists no theoretical basis for determining the geometry of the forming shoulder needed to process particular packaging materials. This paper investigates the application of Euler's theory for material flow around cylinders to the case of forming shoulders used in vertical form–fill–seal systems. It is shown that the theory is indeed applicable, and an inequality relation between the measured coefficient of friction of the material and the forming shoulder parameters is established. It is further shown how this can be used to direct the design of a forming shoulder for a particular application. Copyright © 2011 John Wiley & Sons, Ltd.     

某复杂蒙皮拉形中起皱缺陷的消除

目的对某复杂飞机蒙皮零件在拉形工艺过程中的起皱行为进行研究,以得到消除起皱缺陷的方法。方法分析了该蒙皮零件的型面特点,指出了拉形过程中出现起皱的原因。设计了3种改进的拉形方案,采用有限元仿真的方法对这3种方案进行模拟评估,确定了对起皱缺陷改善最为明显的一种,基于设备与工装的限制对该方案进行了调整,作为改善拉形质量的最终方案,并再次进行了有限元仿真验证。结果根据改进方案,在拉形工艺设计软件上生成拉形设备的数控代码,进行了生产性验证,与有限元仿真结果符合的很好,基本消除了起皱缺陷,提高了零件的成形质量。结论通过对拉形工艺中工装模具的优化设计,可以减少或避免起皱缺陷的出现。     

Experimental evaluation and prediction of forming limit of FSW blanks made of AA 6061 T6 sheets at different weld orientations and weld locations

The main objective of the present work is to predict the forming limit of friction stir welded (FSW) sheets made of AA 6061T6, having different weld orientations, weld locations, and made at two different welding speeds. The predicted forming limit curves (FLCs) are validated with experimental FLCs. The thickness gradient based necking criterion (TGNC) and major strain‐rate ratio based necking criterion (MSRC) are used to predict the forming limit. The significance of single zone model and double zone model in FLC prediction is discussed. A decrease in hardness is witnessed in the weld zone as compared to base material. With increase in shoulder diameter and decrease in rotational speed, hardness has improved in the weld zone. The forming limit predictions of un‐welded sheets and FSW sheets coincide well with experimental results. The predicted FLCs of FSW sheets from TGNC and MSRC are equally accurate as compared to experimental FLCs in all the weld locations. Both TGNC and MSRC predict almost the same forming limit in 90° weld orientation, while TGNC showed better prediction in 45° weld orientation. FSW sheets with double zone models show better prediction accuracy than single zone models in most of the cases, except in the case of weld at centre location and at longitudinal orientation. There is only slight deviation between single zone and double zone model predictions. The failure location and failure pattern predictions are also agreeing well with the experimental FLCs.     

飞机蒙皮多道次滚弯加载轨迹设计方法研究

目的研究针对数控滚弯机的飞机蒙皮多道次滚弯加载轨迹设计方法。方法根据数控滚弯机机构的特点,提取零件截面线,根据截面线曲率进行分段和参数化方法设计加载轨迹,通过反向求解将加载轨迹转换为设备运动参数。结果飞机蒙皮多道次滚弯加载轨迹设计方法有效地提高了工艺参数设计的效率和准确度,并与数控设备相结合,输出了设备的控制参数。结论相比传统的以经验分析和通过反复试弯大致确定工艺程序及参数,并通过人工控制的飞机蒙皮滚弯成形方法具有突出的实质性特点和显著的进步。     

Design of forming shoulders with complex cross‐sections

Vertical ‘form, fill and seal’ machines are used to produce bags for packing particulate or multiple objects. In operation, film is drawn over a forming shoulder and the good design of the surfaces of the shoulder is vital to the successful operation. This paper reviews underlying geometrical definition for the shoulder, corresponding to a filling tube with circular cross‐section. In practice, such cross‐sections occur frequently, but other variant shapes are becoming increasingly common. A method is discussed and demonstrated for extending the approach to allow tubes formed from circular arcs and straight line segments to be handled. Copyright © 2005 John Wiley & Sons, Ltd.     

磁流变软启动传动装置的I-T关系研究

 磁流变软启动传动装置引入磁流变液作为传递转矩的工作介质。介绍了磁流变软启动传动装置的工作原理及基本结构,以Bingham模型和曲线拟合为手段,给出了建立磁流变软启动传动装置输入电流I和输出转矩T的非线性关系的方法,为该装置的可靠设计和有效控制提供了科学理论依据。