不锈钢氮气等离子切割——割炬设计与切割工艺的研究

割炬的内腔参数和结构是影响割炬切割性能的主要因素,试验中选择了合适的内腔参数和结构,设计了轻巧、可靠和性能良好的割炬,同时选择了合适的气体、电极和切割规范参数,顺利地切割了80毫米以下的不锈钢板,质量良好。消除不锈钢切口毛刺是等离子切割应用于生产的关键问题之一。本文探讨了不锈钢切口毛刺形成的原因和各种因素对毛刺的影响,采用了改进割炬的同心度,选择合适的电源功率,调节气体流量和切割速度等简便易行的方法,已使45毫米以下不锈钢切口毛刺消除。     

超大厚度钢锭火焰切割机数控系统软件设计

超大厚度钢锭火焰切割机是为切割大型铸锻件而设计的专用高档数控设备.由于铸锻件毛坯表面为不规则多边形或近似圆形,在传统进行水口和冒口切割时需要不断手动调整割炬高度来保持割炬与工件之间的距离恒定以保证切割效果.为保证全时自动切割,系统运用激光测距传感器采集工件表面形状信息,以IMAC运动控制技术为基础,采用基于组件技术的CAD制图控件和面向对象的软件开发方法设计了一种专用数控系统,实现了手动、半自动和自动的高效切割.     

一种相贯线曲线通用切割机的研制

大直径筒体的相贯线曲线焊接,为了得到高精度的切割尺寸,保证焊接质量,提高切割效率,降低成本。利用正弦曲线机构将简单的机械运动变为割矩端部复杂的曲线运动,实现了相贯线曲线运动轨迹的自动切割,只需改变正弦曲线运动机构的偏心机构回转半径e就可实现不同直径的筒体与接管相交所形成的相贯线曲线的自动切割。该割炬绕工件的转动与上下的同步移动采用直接传动,动作协调、传动平稳,避免了传动积累误差,可在多种位置点火切割,结构简单,操作方便,工作可靠。通过应用,取得了明显的经济效益,降低了成本,提高了效率3～5倍,切割质量稳定可靠。是一种低成本自动化相贯线曲线的自动切割通用设备。经过改进,用焊枪代替割矩,还可对相贯线曲线实现自动焊接。     

数控等离子弧切割多参数的选择与优化控制

数控等离子弧切割是一种经济、实用、高效的先进热切割技术.在数控等离子弧切割工艺参数中,许多参数相互耦合,影响切割质量与切割效率,因此,切割参数的选择及控制是一个重要的问题.通过对数控等离子弧切割的加工工艺进行分析,对等离子弧切割的空载电压、弧柱电压、切割电流、切割速度、工作介质及流量、喷嘴距工件的高度、喷孔直径、电极内...     

球壳瓣片坡口切割的新工艺及其生产应用

本文主要介绍了为保证球罐球壳瓣片坡口的切割质量而提出来的“可调弧轨式”,切割胎、风冷割炬自动升降装置以及用双割嘴切割X型坡口等新装置及新工艺。通过生产实践证明,所切出的坡口质量均可达到我国有关标准的要求。     

提高切割质量的自动调高装置

等离子弧自动切割小车在运行中,往往由于板材凹凸不平或板材与轨道不在同一个水平面上,造成喷嘴与板材间距发生变化,忽高忽低,影响切割质量,严重时还会烧坏喷嘴。为了提高切割质量,改善操作者的劳动强度,切割过程中不受任何条件限制,设计了自动调高装置(右图)。由右图可知,自动调高装置是由支撑、支架以及两个小轴、两个轴套和一个小轮组成,再用一个卡子把它们固定在割炬横架上。支撑和支架均由圆钢和角钢制成。小轮用黄铜制成。轮毂14与轴10之间能自由旋转,间隙为0.2～0.3mm。钢轮15与割炬喷嘴13之间距离     

数控火焰和等离子高低调节器的原理及应用

由于切割机在工作过程中不能准确探知切割割炬与钢板的距离,影响焊接质量,提出了一种数控火焰和等离子调高闭环自动控制系统.详细介绍了控制系统中的电容传感器、高频滤波电路、差分运算放大器、比较器、霍尔传感器、触发器、断弧提升器、模拟开关手动/自动转换器、定位起弧电路、手动/自动振荡器、光电藕合与电机驱动电路等的组成和原理.经实际应用证明,该控制系统切割后工件质量好,能达到切割精度要求,同时还能减轻操作者劳动强度.     

激光切割吸种盘的工艺研究

对吸种盘进行激光切割试验,探讨其工艺特点,分析不同的切割参数如激光功率、切割速度、辅助气体压力对切割质量的影响,给出Nd:YAG激光器切割吸种盘的具体方法.实验结果表明,只要工艺参数选择适当,可获得很好的切口质量,且能提高生产效率.     

高炉风口法兰安装孔的切割

高炉风口切割质量的好坏,直接影响高炉的质量。由于风口区的炉体为锥形(图1),采用割炬直接切割时,操作者不但需要不断地移动位置,而且还要不断地改变割炬的角度,使切割质量得不到保证,从而影响了安装与焊接质量。为此而研制的高炉风口法兰安装切割     

全数字化下料工艺研究与应用

传统下料方式切割效率低、质量不稳定、人为因素大、造成严重浪费.全数字化下料具有自动上下料、自动清渣、自动喷码和分拣物料、自动监控、自动校枪、自动换刀钻孔攻丝、五轴联动、立体切割等各项功能,可有效提高生产效率,改善切割质量.集下料、开坡口、钻孔攻丝于一体,最大限度减少了各种浪费,提高了下料效率,是衡量下料工艺装备水平的重...     

CAPP环境下的切削用量优化研究

切削加工工艺参数的选择对提高生产率、加工质量、经济效益等各方面具有重要的作用,针对当前CAPP系统中切削用量的优化仍存在着优化方法复杂、低效、容易收敛于局部最优解等问题,本文引入遗传算法思想,以优化CAPP环境下的切削加工工艺参数,克服应用传统优化方法的缺陷。     

Analytical models for high performance milling. Part I: Cutting forces, structural deformations and tolerance integrity

Milling is one of the most common manufacturing processes in industry. Despite recent advances in machining technology, productivity in milling is usually reduced due to the process limitations such as high cutting forces and stability. If milling conditions are not selected properly, the process may result in violations of machine limitations and part quality, or reduced productivity. The usual practice in machining operations is to use experience-based selection of cutting parameters which may not yield optimum conditions. In this two-part paper, milling force, part and tool deflection, form error and stability models are presented. These methods can be used to check the process constraints as well as optimal selection of the cutting conditions for high performance milling. The use of the models in optimizing the process variables such as feed, depth of cut and spindle speed are demonstrated by simulations and experiments.     

基于Multi-Island GA数控加工切削用量优化

切削用量的选择对刀具耐用度、产品的加工效率以及加工质量等都有直接影响。为选取合理的切削用量,以最大生产效率为目标,建立铣削加工优化模型。结合实际加工中不同约束限制,采用改进遗传算法(Multi-Island GA)对目标函数寻优求解。将优化后的结果与切削用量手册经验值相对比,切削用量的选取得到了有效改善,并提高了铣削加工的生产效率,且优化结果验证了算法的可行性。     

Modeling and simulation of 5-axis milling processes

5-axis milling is widely used in machining of complex surfaces. Part quality and productivity are extremely important due to the high cost of machine tools and parts involved. Process models can be used for the selection of proper process parameters. Although extensive research has been conducted on milling process modeling, very few are on 5-axis milling. This paper presents models for 5-axis milling process geometry, cutting force and stability. The application of the models in selection of important parameters is also demonstrated. A practical method, developed for the extraction of cutting geometry, is used in simulation of a complete 5-axis cycle.     

加工复合地板耐磨层时PCD刀具切削参数的研究

切削参数是影响PCD刀具切削性能的主要因素。本文采用Element Six公司的SYNDITE CTH025型聚晶金刚石(PCD)复合片制成强化复合地板用切削刀具，进行了一系列加工强化复合地板耐磨层的切削实验。通过实验研究了切削参数对刀具切削力的影响，得出了切削力随切削参数的变化规律，指出随着切削深度的增加，PCD刀具切削力增加；进给速度的增加使切削力增加；切削速度的增加将会使切削力降低。同时，分析了切削参数对刀具磨损、工件加工质量以及加工效率的影响。最后，本文总结了采用PCD刀具加工强化复合地板时加工参数的选择原则，认为当n=6000r／min、f=10000mm／min能够实现较高的加工效率，并保证工件的加工质量。     

数控火焰切割机切割质量的参数控制

影响数控火焰切割机切割质量的因素有氧气的纯度、预热火焰功率及时间、氧气压力、切割速度、割嘴到工件的距离等。通过对实验及现场实际切割参数的整理分析,得出切割质量的参数控制表,以供参考。     

Parametric investigation of CO2 laser cutting of 2024-T3 alloy

Influence of processing parameters and optimal conditions for CO₂ laser cutting of an aluminium–copper alloy (2024-T3) have been determined. Results are evaluated in terms of productivity (i.e. cutting speed) and cut quality. Moreover, main observed effects in each processing mode are discussed.Superior cut quality is obtained when processing in CW mode versus pulsed mode. The results obtained allow affirming that adopting the necessary precautions for preventing laser beam backreflections and under optimized processing conditions (here identified), sound cuts can be made in 2024-T3 Al alloy. This opens a new sort of materials to be cut by existing CO₂ laser cutting machines.     

基于人工智能算法的最优加工表面粗糙度预测研究

以切削速度、进给量、切削深度、刀尖圆弧半径为设计变量,采用正交试验法进行了立方氮化硼(CBN)刀具干式车削冷作模具钢Cr12MoV的试验研究。利用神经网络的非线性拟合能力和遗传算法的全局寻优能力,建立了加工表面粗糙度预测模型并获得了使表面粗糙度达到最优的切削用量与刀尖圆弧半径组合。利用遗传算法获得的最优表面粗糙度值比田口方法和切削试验所获得的最佳表面粗糙度值分别降低了7.1%和17.2%。文中所采用的方法也为切削加工中刀具磨损、切削力和残余应力等问题的建模与参数优化提供理论参考。     

Machining prediction of spindle–self-vibratory drilling head

The drilling of deep holes with small diameters remains an unsatisfactory technology, since its productivity is rather limited. The main limit to an increase in productivity is directly related to the poor chip evacuation, which induces frequent tool breakage and poor surface quality. Retreat cycles and lubrication are common industrial solutions, but they induce productivity and environmental drawbacks. An alternative response to the chip evacuation problem is the use of a vibratory drilling head, which enables the chips to be fragmented thanks to the axial self-excited vibration. Contrary to conventional machining processes, axial drilling instability is sought, thanks to an adjustment of head design parameters and appropriate conditions of use. A dynamic high-speed spindle/drilling head/tool system model is elaborated on the basis of rotor dynamics predictions. In this paper, self-vibratory cutting conditions are established through a specific stability lobes diagram. Investigations are focused on the drill's torsional–axial coupling role on instability predictions. A generic accurate drilling force model is developed by taking into account the drill geometry, cutting parameters and effect of torsion on the thrust force. The model-based tool tip FRF is coupled to the proposed drilling force model into an analytical stability approach. The stability lobes are compared to experimentally determined stability boundaries for validation purposes.