CO2焊机一元化智能控制系统

研制了CO2 焊接电弧电压的一元化自寻优微机智能控制系统 ,此系统能根据CO2 焊接电流的设定值对电弧电压进行自寻优调节 ,使焊接参数达到最佳配合。智能控制系统主要由弧压模糊控制模块、焊接电流控制模块与一元化推荐表组成。弧压模糊控制模块以CO2 焊接过程中的熔滴过渡频率 fd、燃弧时间与短路时间的比值tas与短路周期标准差σ等特征参数的综合值作为判据进行弧压寻优。样机试验结果表明 ,此智能控制系统能显著改善CO2 焊机性能 ,降低焊接飞溅。     

火电厂非热力系统压力容器常见失效形式分析

针对火电厂非热力系统压力容器空气缓冲罐严重腐蚀、壁厚减薄,空气储罐筒体裂纹,空气干燥器严重鼓包3种失效形式,介绍检验情况,分析失效原因,并提出针对性的防范措施及建议。     

车载空调控制器的新型按键旋钮溃缩设计

本文针对乘用车内部凸出物的法规要求对车载空调控制器的旋钮按键溃缩进行了研究和设计，描述了这种新型旋钮按键溃缩设计相对于目前常用的方案在成本、空间、可靠性等方面的优势。根据实际设计结果表明，本文所应用的新型旋钮按键溃缩设计能在成本与空间有限的情况下可靠的满足法规对乘用车内部凸出物的要求，为乘用车内部凸出物溃缩方案提供了新方向，值得我们推广应用。     

我国高压SF6断路器的现状及发展趋势

介绍了高压SF6断路器的发展概况,并对高压SF6断路器的性能和灭弧方式进行了着重的阐述.最后结合科学技术的发展,对瓷柱式和罐式SF6断路器的发展趋势作了较为详细的论述.     

基于UG的冰箱旋钮开关注射模设计

在分析冰箱旋钮开关注射成型工艺和塑件结构特点的基础上,基于UGNX7．0软件进行注射模设计,该模具采用1模两腔、潜伏式浇口、斜导柱斜滑块侧抽芯。同时利用Vbasic软件设计程序计算斜导柱的长度。最后利用UG软件的制图模块生成工程图。     

Ergonomics aspects of knob designs: a literature review

Hand-related apparatus designs that fail to accommodate appropriate hand postures can cause hand-related musculoskeletal disorders. While there have been studies on the handling and design of various hand-related apparatus, little has been written on the ergonomics aspects of knob designs. The aim of this paper is to review various knob designs and their ergonomics aspects. The literature review suggests that gearshift knobs, door knobs, gas valve knobs, butterfly nuts and screw knobs are common knobs used for daily living activities. Other knobs like the convex, knurled, spherical, cone-shaped and ridged knob are often used for industrial-related applications. The ergonomics considerations identified in knobs include aesthetic attraction, position, torque requirement and shape-coding. This literature review can be used as groundwork for the development of ergonomics theory and hand-related studies. Engineers can use this literature review to identify certain ergonomics aspects in knobs to improve equipment designs, operating efficiency and working comfort.     

Carcass fat partitioning and meat quality of Alentejana and Barrosã young bulls fed high or low maize silage diets

This study assessed the effect of breed and diet on carcass composition, particularly fat partitioning, and meat quality in young bulls. An experiment with forty young bulls from two phylogenetically distant Portuguese bovine breeds, Alentejana and Barrosã, fed two diets with different maize silage to concentrate ratios, but isoenergetic and isonitrogenous, was carried out until the animals reached 18 months of age. In the longissimus lumborum muscle, Barrosã bulls fed the low silage diet had the highest intramuscular fat (IMF) content. Bulls fed the low silage diet also had the highest IMF content in the semitendinosus muscle. Diet determined the proportions of total visceral fat and individual fat depots. Under these experimental conditions, it was shown that the genetic background is a major determinant of carcass composition and meat quality, and that the dietary differences studied had limited effect on carcass composition.     

双色内螺纹旋钮的热流道注塑模设计

以内螺纹旋钮的双色注射模为例.阐述双色注射模热流道的结构特点、设计要点以及工作过程.通过对塑件结构特点的分析,确定注塑模具的整体设计方案,并对模具设计过程中的要点和难点进行分析.并介绍一种内螺纹自动脱模机构.该模具的设计方法对双色注射模具设计具有一定的指导意义.     

CO2短路过渡焊电弧电压自寻优模糊控制系统

CO2 短路过渡焊机一元化控制是通过单旋钮将影响短路过渡频率的主要规范参数电弧电压和焊接电流有机结合在一起 ,通过单旋钮调节焊接电流 ,电弧电压随电流相应变化 ,形成最佳匹配而获得最高短路过渡频率。但由于CO2 短路过渡过程目前尚难以用精确数学模型来描述 ,所以通过一般控制方法所实现的一元化控制并未真正实现单旋钮调节。针对这一不足 ,研究了一种以 16位 80C196KC数字单片机为核心器件通过软件方式实现的CO2 短路过渡焊电弧电压自寻优模糊控制系统。系统以操作者所选择的焊接电流为唯一设定参数 ,自动对电弧电压进行以实现最高短路频率为目标的自寻优 ,可使此类焊机实现真正单旋钮调节为特征的一元化控制     

一种专用电路模块测试台的设计与使用

对于技术指标不多、形状规则的电路模块,采用常规的测试夹具和测量仪器就可以达到测试要求。但对于技术指标繁多,测试过程复杂的专用电路模块,利用常规的测试方法,工作效率低下,而且会出现因电源线的极性接反而烧坏产品的现象。因此,设计制作了专用的测试台。根据专用电路模块技术指标的要求,确定了测试台的设计方案。通过测试方法的详细说明,体现了该测试台对技术指标测试的全面性,达到了测试目的,解决了专用电路模块的生产瓶颈,大大提高了工作效率。