利用空气保护罩对水中管道进行切割的工艺措施

1问题的提出 众所皆知，普通的氧-乙炔割炬是利用高温的金属在纯氧中燃烧而将工件分离的加工方法。气割时，先用氧-乙炔火焰将金属预热到燃点，然后打开切割氧阀门．使高温金属燃烧，金属燃烧时所产生的氧化物熔渣被高压氧吹走，形成切口，如图1所示。     

手工空气等离子切割技术及应用

介绍了几种常用空气等离子切割机主要技术参数。针对手工切割机,特别强调了三个重要工艺参数:切割速度、喷嘴高度和喷嘴角度,并提出具体要求。明确割口质量要求,对常见缺陷具体分析并提出相应预防措施。详细说明操作步骤、操作要领和割口质量检验。手工空气等离子切割机产生的电击、辐射、灰尘烟气等危害要强于焊条电弧焊,安全防护技术可对操作者提供可靠指导。     

手工等离子弧切割应用指导

１９５４年 ,等离子弧切割发明于硬质合金联会Ｌｉｎｄｅ分部Ｔｏｎａｗａｎｄｅ实验室 ,现在那里已是ＥＳＡＢ焊割设备产品制造分部。当时 ,年轻的科学家罗伯特·乔治发现 ,迫使气体保护下的钨极电弧通过小孔集中 ,弧的温度和密度会大大增加 ,这一过程类似于光束通过透镜聚集。当相当高速的的气流通过这种聚焦弧时 ,就能用其切割金属。弧极高的温度（通常可达到２５００℃或更高）熔化金属 ,同时高密度气流吹去切口的熔化粘渣 ,分离被切割体。由于弧中气体处于超热离态称为等离子体 ,这一过程便称为等离子弧切割。１手工等离子弧切割基本常…     

空气等离子切割技术的应用

近年来，空气等离子切割庆我国的应用越来越广泛，目前已有几十个厂家生产空气等离子切机，由于设备的制造标准及性能检测标准不统一，给用户在选择设备、用好设备及对设备的维修带来了困难。本文从等离子弧的特点出发，综合论述了空气等离子切割技术应用，设备选择、操作及维修。     

空气等离子弧切割的特点

<正>空气等离子弧切割是指用压缩空气作离子气,用压缩空气电离后产生的电弧热进行切割的切割方法。在电弧作用下,电离了的空气等离子体热焓值高,因而电     

提高空气等离子弧切割质量的工艺措施

ＬＧ５０Ｋ空气等离子弧切割机喷嘴烧损快,割枪、焊割线和电器元件也时有损坏,切割质量不理想。通过正交试验和分析,找到了原因,提出了解决措施和最佳切割工艺参数;采用双机并联,可进一步提高切割厚度、切割速度和切割质量。１　影响等离子弧的参数等离子弧的形成与电压高低、电流大小、压缩空气的压力和流量、电极与喷嘴的同心度、电极与喷嘴的距离、喷嘴直径有着密切关系,这些参数和切割速度是切割质量和喷嘴寿命的直接影响因素。为了摸索各个因素的影响程度,进行了下述正交试验。２　正交试验表１　因素水平表Ｌ１６（４４）…     

空气等离子切割烟尘产生的特点及收集方式

一年一度的慕尼黑上海电子展（electronica＆Productronica China）于2006年3月21日在上海新国际博览中心拉开了帷幕。经过在中国的四年培育,第五届慕尼黑上海电子展已不再局限于电子业生产厂家展示新品的平台,更重要的是它已经成为中国,乃至全球电子行业领军企业济济一堂交流经验、寻找商机、预测行业发展方向的年度盛会。     

国外小电流空气等离子弧切割技术的发展

本文就小电流空气等离子弧切割工艺的特性、切割质量、切割设备、存在问题和应用情况作了综合介绍。当工作气体含氧量为20％时,切割速度急剧增加,大大优于气割。     

钢材切割现状及Fast切割软件的应用

现代切割技术有别于传统手工切割技术．它是基于现代计算机信息技术．针对不同的切割下料设备。对传统切割技术加以改进提高，发展成为以优化套料技术、钣金展开技术和数据库管理技术为代表的计算机辅助切割生产和管理软件。以有效提高钢材综合利用率，提高切割效率和切割质量．加强切割生产管理。     

Materials for electromagnetic interference shielding

Materials for the electromagnetic interference (EMI) shielding of electronics and radiation sources are reviewed, with emphasis on composite materials and resilient EMI gasket materials, which shield mainly by reflection of the radiation at a high frequency.     

Polypyrrole composites for shielding applications

This article highlights the physical properties of polypyrrole (PPy) coated over MnZn ferrite (MZF), nickel coated over PPy, and PPy coated over Ni-MZF magnetic core particles. The commercial ferrite and Ni-ferrite particles are primarily used, and the PPy-ferrite particles with composite structure are synthesized both via an oxidative polymerization of pyrrole in an aqueous solution, which contains well-dispersed ferrite particles, and electrochemical polymerization technique in acetonitrile (ACN). The materials have been processed in the form of coatings, films, and sheets by blending of conventional polymer such as polyurethane (PU) wherein the composites retain the mechanical properties of the conventional polymers and the electrical conductivity of the conducting polymers. The influence of ferrite content with respect to the electrical and ferromagnetic properties of PPy composites were investigated by electrochemical impedance spectroscopy (EIS) and dc field-cooled, zero-field cooled susceptibilities and M–H loop measurements. Their structural characterization is also discussed based on Fourier transform infrared (FTIR) and the X-ray diffraction (XRD) measurements. The shielding effectiveness (SE) properties will be reported in our future studies.     

头盔硬衬垫机动发泡模设计

介绍头盔硬衬垫机动发泡模的设计,研究了汽室和型腔板的结构,实现不同型号头盔硬衬垫模具零件的标准化、通用化设计;合理选择进料口位置、透气塞分布方式保证预发颗粒充分融合;采用联动抽芯机构实现型面法相斜孔的自动成型。生产实践证明:模具结构自动化、通用化程度高,成型的零件质量达到使用要求。     

Identification of the specific cutting force for geometrically defined cutting edges and varying cutting conditions

Cutting force modeling is a major discipline in the research of cutting processes. The exact prediction of cutting forces is crucial for process characterization and optimization. Semi-empirical and mechanistic force models have been established, but the identification of the specific cutting force for a pair of tool and workpiece material is still challenging. Existing approaches are depending on geometrical idealizations and on an extensive calibration process, which make practical and industrial application difficult. For nonstandard tools and five axis kinematics there does not exist a reasonable solution for the identification problem.In this paper a co-operative force model for the identification of the specific cutting forces and prediction of integral forces is presented. The model is coupled bidirectionally with a multi-dexel based material removal model that provides geometrical contact zone information. The nonlinear specific forces are modeled as polynomials of uncut chip thickness. The presented force model is not subjected to principal restrictions on tool shape or kinematics, the specific force and phase shift are identified with help of least square minimization. The benefit of this technique is that no special calibration experiments are needed anymore, which qualifies the method to determine the specific forces simultaneously during the machining process. In this paper, experiments with different cutting conditions are analyzed and systematically rated. Finally, the method is validated by experiments using different cutting conditions.     

头盔PUR硬衬垫发泡模设计

通过对PUR泡沫塑料衬垫的形体进行分析,采用2处分型面将整体凹模分成大、小凹模再与凸模组合形成型腔,可保证衬垫成型质量及克服各种障碍体对衬垫脱模的阻挡,大、小凹模通过3处凸台和凹槽的过渡配合,确保大、小凹模的正确定位与连接,采用活动螺钉、开口垫圈与圆柱螺母组成的紧固机构控制凸、凹模的开启和闭合,采用翘板保证衬垫平稳脱模,实践证明,该发泡模生产的衬垫满足使用要求。     

切削温度与切削力综合测量的虚拟仪器

介绍了综合测量切削平均温度和三向切削力并对其进行分析处理的虚拟仪器.利用PCI-1 200卡采集热电偶测温仪和电阻应变式测力仪传输的数据.利用LabVIEW平台开发.具有显示 力和温度波形曲线、热电偶标定和测力仪刻度标定、确定切削温度和切削力指数公式的能力 .提出了基于切削力和切削温度信息的切削状态判定方法.     

切削温度与切削力综合测量的虚拟仪器

介绍了综合测量切削平均温度和三向切削力并对其进行分析处理的虚拟仪器。利用PCI－1200卡采集热电偶测温仪和电阻应变式测力仪传输的数据。利用Lab VIEW平台开发。具有显示力和温度波形曲线、热电偶标定和测力仪刻度标定、确定切削温度和切削力指数公式的能力。提出了基于切削力和切削温度信息的切削状态判定方法。     

屏蔽罩级进模设计

分析了屏蔽罩零件的成形工艺,介绍了零件排样、模具结构设计和模具关键零件的详细结构设计。模具结构可靠,设计合理,能保证生产零件的质量,满足大批量生产要求。