低压化成箔的国产化

目前大部分铝电解电容器生产厂家的铝箔需要进口,尤其是低压高比容的化成箔,影响电容器的生产成本。近年来, 浙江横店化成箔厂在低压化成箔生产技术方面取得较大突破, ２５ Ｖ及３５ Ｖ化成箔经样品认定、小批量试用及大批量使用表明： ２５ Ｖ及３５ Ｖ １３ ｍ ｍ 以上产品的化成箔可实现国产化     

腐蚀环境下自冲铆接头竞争失效机制及力学性能分析

为研究腐蚀环境下自冲铆接头失效模式的转变机理和力学性能特征,采用0.6 mol/L的NaCl溶液对多组自冲铆接头进行周浸腐蚀试验,通过力学测试和扫描电子显微镜对接头的力学性能及失效模式进行分析. 结果表明,异质接头的失效模式随腐蚀周期延长由 Ⅰ 向 Ⅲ 转变,转变速率取决于接头材质,同质接头的失效模式不受腐蚀周期的影响. 短期腐蚀下,搭接区板间腐蚀产物使得同质和异质接头失效载荷均有所上升;异质接头上升幅度较大,腐蚀后期其失效载荷较同质接头损失严重. 异质接头稳定性较差,凸模制备的同质组合接头较平模稳定性好. 异质接头电化学腐蚀剧烈,下板铆接点底部材料的脱落由应力集中所产生的撕裂纹所致.     

针对飞机小曲率结构的半自动化电磁铆接系统设计

为解决飞机手工铆接一致性差、劳动强度高等问题,设计一种带托架的半自动化电磁铆接系统,由控制单元、装配型架单元、回形托架单元、门形框单元、铆接单元和顶把单元组成。控制单元控制整体系统运动和施铆;装配型架单元为工件及其他单元的装夹提供刚度支撑;回形托架单元和门形框单元共同作用,保证铆接单元和顶把单元同步联动,实现电磁铆接的单人操作;回形托架单元利用平衡气缸克服铆接单元和顶把单元重力。针对铆接后坐力大的问题,设计缓冲器、顶持气缸双重减振结构来减弱后坐力对操作者的影响;同时根据不同铆钉直径所需铆接力的要求,通过调节顶持气缸压力以适应不同的铆接后坐力。托架坐标系X、Y、Z 3个方向均安装直线导轨,用于铆接单元与顶把单元铆接定位过程的同步导向,保证铆接一致性。利用托架的电磁铆接作业流程进行了5 mm铝铆钉的工件铆接试验。结果表明：所设计的系统能够完成小曲率壁板结构半自动化铆接。     

Fatigue and impact analysis and multi-objective optimization design of Mg/Al assembled wheel considering riveting residual stress

The multi-material assembled light alloy wheel presents an effective lightweight solution for new energy vehicles, but its riveting connection remains a problem. To address this problem, this paper proposed the explicit riveting-implicit springback-implicit fatigue/explicit impact sequence coupling simulation analysis method, analyzed the fatigue and impact performance of the punching riveting connected magnesium/aluminum alloy (Mg/Al) assembled wheel, and constructed some major evaluation indicators. The accuracy of the proposed simulation method was verified by conducting physical experiments of single and cross lap joints. The punching riveting process parameters of the assembled wheel joints were defined as design variables, and the fatigue and impact performance of the assembled wheel was defined as the optimization objective. The connection-performance integration multi-objective optimization design of the assembled wheel considering riveting residual stress was designed via Taguchi experiment, grey relational analysis, analytic hierarchy process, principal component analysis, and entropy weighting methods. The optimization results of the three weighting methods were compared, and the optimal combination of design variables was determined. The fatigue and impact performance of the Mg/Al assembled wheel were effectively improved after optimization.     

低压交流接触器铁心底面平面度超差的原因分析及解决措施

低压交流接触器铁心通过硅钢片冲压、叠铆、极面磨削和喷油等加工工艺制造完成。铁心冲片后铆压是铁心加工的一个重要工序,而铆压工艺质量控制的好坏是造成铁心底面平面度超差的主要原因,也是影响后道工序和整个产品性能质量的重要标志。介绍了低压交流接触器铁心底面平面度超差产生的主要原因及基本的解决措施,为低压交流接触器铁心的制造提供了一定的技术参考。     

6303轴承内径尺寸复检铆合模的设计

针对6303轴承成品内径尺寸达不到100%合格、个别产品内径存在露黑皮现象,在原铆合模的结构中增加了内径尺寸复检心轴,有效地防止了内径露黑皮产品流入下工序,使内径尺寸达到100%合格,且不影响生产效率。     

Experimental and numerical appraisal of self-piercing riveting

Self-piercing riveting (SPR) has become an interesting alternative joining technique for difficult to weld materials. A limitation of this technology is still the heavy experimental procedure needed for joint optimisation. In this paper, an experimental activity on Al6082-T4 sheet metal samples has been conducted to achieve a better understanding of the process. The joining process and the tensile tests have then been simulated using a FE code to predict deformed shape, failure mechanism (e.g. crack propagation, rivet pull-out) and shear resistance of the joint. Results show how this procedure can be a powerful tool for joint optimisation.     

铝钢点焊铆接复合连接技术

提出了一种点焊与铆接复合进行铝钢连接的技术,即在待焊试样区域预制工艺孔,将铆钉铆入孔中,利用铆接力实现试样的预连接.然后使用点焊机在铆接位置进行点焊,实现铆接与点焊的复合连接,称为"点铆焊".文中分析了该方法的力学性能、微观组织、断裂模式,并同纯点焊与纯铆接进行了比较.结果表明,点铆焊的抗拉强度比纯点焊提高了23.8%,比纯铆接提高了28.7%,失效前吸收功比纯点焊提高211%,比纯铆接提高67%.虽然在点铆焊过程中也会产生脆性金属间化合物,但这些区域并不是主要的承载部位,点铆焊为塑性断裂模式.     

异种金属材料自冲铆接头位置对疲劳强度的影响

为了提高结构件的疲劳性能,基于大量实验研究了自冲铆接头位置布置对剪切结构件疲劳强度的影响。通过改变铆钉个数、搭接尺寸、最大循环载荷、铆钉到板长及板宽的边距等因素,对12种不同铆接位置的结构件进行了静力学实验,并在此基础上进行疲劳实验。实验结果表明:在搭接尺寸不变的情况下,铆钉到板长或板宽的距离过大或过小均会降低结构件的疲劳强度;结构件疲劳寿命随最大循环载荷的减小而增大;在一定范围内,结构件疲劳强度随搭接尺寸的增大而增大,随后呈降低趋势;二钉结构件的疲劳寿命显著高于单钉结构件的疲劳寿命,但并不随铆钉个数呈倍数的关系增长。     

一种基于DSP控制的飞机电磁铆枪控制电路设计

设计一种基于DSP控制的飞机电磁铆枪控制电路,依据电磁铆枪在飞机构件铆接过程中的技术要求,设计出充电电压采集电路、充电回路控制电路以及放电回路控制电路.