一种参数化图形库的建立方法

本文阐述了机械CAD系统开发过程中的关键技术:参数化图形库的建立方法及其建立后的图形库的管理。同时还介绍了几个在开发过程中为减轻编程工作量作者自己编制的自定义函数。     

DFA中零件对称性特征自动识别

零件的对称性等形状特征是可装配性设计(DFA)中评价其可装配性好坏的重要指标。针对零件对称性的自动识别问题,提出了一种基于“射线探测”的新方法。主要论述了射线探测的基本原理以及将其运用于对称性识别的实现过程,并对识别程序的运行结果做了评测,证实了这种方法的可行性和有效性。     

高速低噪声锭子

本文研制了一种双弹性支承的高速低噪声锭子。上轴承支承的弹性系数根据有限元分析来确定,弹性支承形式采用橡胶吸振圈,橡胶吸振圈的参数设计满足弹性系数的要求,该双弹性支承锭子适宜于高速且噪声低,已获高速低噪声锭子中国专利。     

用频域分析法研究纺机高速回转件的振动和噪声

本文介绍了利用B&K3360声强分析仪及频率分析系统对锭子和气流纺纱高速轴承组件的振动、噪声进行频谱分析,以了解两者的主频率及相互关系。锭子的噪声频率在200赫—5千赫,主要与转速频率及其谐波有关。自激振动的频率对噪声影响不大。噪声的声压级在16,000转/分以上时有明显的增加。刚性支承的气流纺组件的噪声频率较高。而具有弹性支承的气流纺组件的噪声主频率峰值与振动的第一、二、三阶自然频率相一致,说明两者有相关。     

变质量锭子系统对自身不均衡的强迫响应

在纺纱过程中,纱线不断卷绕到纱管上去,锭子纱管系统是变质量系统,本文利用摄动法对其动力学方程求解。得出如下结论:变质量的锭子纱管系统临界转速形成为一区域,锭子设计应避开这一区域.     

新课程改革与中学化学教学的素质教育

中学化学教学应以提高和发展学生的科学素养为中心,学生学习方式由被动、接受的学习向主动、合作、研究性学习转变.教学过程是实现课程目标的重要途径,必须突出对学生创新意识和实践能力的培养,优化教学过程。     

NEW METHOD FOR PART SYMMETRY AUTOMATED RECOGNITION IN DFA

Design for assembly (DFA) evaluation has preved to be a systematic approach in determining how well a product is designed from the point of view of assembly. Geometric feature, such as symmetry, is an important factor when evaluating the assemblability of a part in it. But the automated detection of symmetry has always been considered to be a difficult problem which requires great effort. Proposed here is a new method for part symmetry automated recognition. The method is based on ray detecting theory and can effectively recognize the symmetry of parts with various shapes. It is of great importance to linking together DFA evaluation procedure with CAD model.     

Study on the Splicing Principle of the Air Splicer for Auto-coner

The shaping form of an untwisted yarn-end for the airsplicer is analyzed and then a cosine curve formwhich will have practically good splicing effect isproposed. The yarn motion in the splicing nozzle by     

CALCULATIONS AND ANALYSIS OF THE SPINNING ROTOR BEARING SYSTEM BY USING FEM

In this paper the formulation of finite element analysis for frame casing problems of theharmonic type is described. Attention is paid to the OE spinning rotor bearing assembly (RBA)' sdynamic model, whose harmonic parameters, such as natural frequencies and modal shapes, aresolved by means of structural analysis program using personal computer, i.e. SAP84 software. Ac-cording to orthogonal factorial design table (OFDT), the predominant sensitive influential factors(PSIF) of RBA are determined.     

环锭纺纱卷绕张力的计算与测试

本文通过对环锭纺纱任意一卷绕层的研究,提出该任意卷绕层的卷绕张力计算公式.由此方便地得到整个卷绕时的卷绕张力。本文同时提出了一种测试卷绕张力的方法,两者的结果是相符的。据此得到了卷绕张力与钢丝圈转速、钢丝圈重量等因素的关系。