圆环内圆磨削的有限元仿真

对二维圆环内孔磨削的温度场和应力应变场用有限元方法进行了仿真.用命令流方式建立了圆环传热有限元分析模型,采用外圆夹紧与盘面夹紧方式进行了对比,计算得到工件的温度场基本上呈环状分布,周向基本均匀,径向温度梯度较大;内孔最大热变形出现在夹紧位置之间,达到了0.030mm,外圆最大热变形达到0.062mm,内孔磨削后将产生较...     

浮动式六爪卡盘的改制与应用

针对三爪卡盘夹持薄壁工件时易变形的问题,介绍了一种在三爪卡盘基础上改制出原理可靠、结构简单的浮动式自定心六爪卡盘的方法,实现了改制后的卡盘在六爪联动同时能保证浮动接触、定心夹紧和稳定可靠,减少了薄壁工件夹紧变形。检测数据证明,浮动式自定心六爪卡盘能极大提高薄壁工件的加工精度。     

偏心内圆类轴承零件磨削加工用夹具的设计

设计了一套专门用于磨削加工偏心内圆类工件的可调夹具,以在内圆磨床上磨削三叉式等速万向节钟形罩为例介绍了夹具的结构及工作原理。该夹具以端齿盘为精密分度装置,结合三爪自定心卡盘机构,可实现一次装夹、多工位加工,适合磨削分度精度高的中小型工件的偏心内圆。     

内圆磨削过程的有限元数值模拟

针对现有磨削零件的热损伤,以圆环内圆磨削为例,基于有限元分析方法,采用命令流方式建立了圆环传热的二维有限元分析模型,对磨削温度场、热变形过程进行了模拟仿真。计算结果得到工件的温度场基本上呈环状分布,周向基本均匀,磨削内圆进入了垫}生状态,磨削内圆时的热变形基本是对称的。分析结果合理可行,为实际切削奠定理论基础。     

FST-009数控车床夹具的改进

FST-009数控车床夹具的设计存在一定的问题,依据设备说明书的转速加工Φ45~60mm之间滚子时,因夹紧力不够,出现让刀、工件转动等现象;当降低转速加工Φ45~60mm之间滚子时,虽能满足要求,但大大降低了生产效率,无法充分发挥该类设备的利用率。为了不降低转速同时又能够加工Φ45~60mm之间的滚子,对夹具进行了改进,由三爪夹盘改为弹性夹盘,使设备的利用率提高了一倍,满足了生产需要。     

高速精密动力卡盘分析与建模

高速精密动力卡盘设计要求载荷大、变形小、安全系数高,通过建立高速精密动力卡盘在切削力作用下的卡盘高爪受力模型,分析了带离心力补偿机构的卡盘结构,并针对刚度对称的卡盘提出了精密的夹紧力损失模型,为动力卡盘的优化设计提供了重要的理论参考.     

高速精密动力卡盘分析与建模

高速精密动力卡盘设计要求载荷大、变形小、安全系数高,通过建立高速精密动力卡盘在切削力作用下的卡盘高爪受力模型,分析了带离心力补偿机构的卡盘结构,并针对刚度对称的卡盘提出了精密的夹紧力损失模型,为动力卡盘的优化设计提供了重要的理论参考。     

主减速器壳体车削工装夹具设计

针对主减速器壳体在立式多刀半自动车床上加工时,采用标准液压三爪卡盘无法有效定位夹紧工件的问题,依据工件的结构特点,设计制造一种能在一次装夹下完成粗精两序加工的专用车削工装夹具,彻底解决了由于多刀同时粗加工、车削抗力大,工件夹持不可靠的安全问题。通过夹紧力的高低压转换,有效防止工件夹紧变形。生产实践证明,该夹具简单可靠,便于操作,提高了生产效率,保证了加工精度。     

偏心件车削加工方法

针对偏心工件车削加工特点,分别介绍了三爪卡盘车削、四爪卡盘车削、两顶尖车削和专用夹具车削加工方法.说明了三爪卡盘加工偏心工件时垫片厚度与偏心距的计算、修正方法以及相互之间的关系.探讨了偏心工件车削加时需要注意的事项.     

圆环内圆磨削的热变形有限元仿真

本文运用热弹性力学原理,结合圆环内孔磨削的实际情况,进行合理的简化和假设之后,建立了圆环内孔磨削的热力学数学模型,利用有限元分析软件ANSYS,对热传递过程和热变形过程进行了仿真,得到了磨削工件的温度场分布云图和热变形情况,进而分析了磨削过程中磨削圆环的温度分布及热变形误差。模拟结果较真实地反映了圆环内孔磨削热状况,为解决圆环内孔磨削表面热损伤和热变形等问题提供了依据。     

Study of a clamping process with no deformation for a thin substrate using a freezing pin chuck system

In planarizing a thin substrate, it has been difficult to remove warp or waviness as such substrates are forcibly deformed by conventional clamping methods. To clamp a thin substrate with no deformation, we have developed a freezing pin chuck system that fixes a thin substrate by freezing the fixation liquid on many pins. This paper describes the precision and fixing characteristics of this newly developed clamping process. The process consists of temperature control of the chuck, a spraying method to form droplets having concurrently uniform height on all pins, and a placing and fixing method that uses melting and refreezing steps so as to not impart shock on a wafer. Fixing strength in the shearing direction achieved more than 110 kPa, and the maximum deformation using the proposed clamping process achieved only 10 μm for a wafer 300 mm in diameter, 1.2 mm in thickness, and 100 μm in warp. Additionally, it is shown theoretically that the cause of slight deformation in this clamping method is the attraction imparted by the meniscus force.     

薄环精密件的高精度、高效率的端面磨削

薄环精密件的高精度磨削一直是磨削领域中重要的研究内容,薄环零件的刚性差,而且热容量小,磨削热量又比较大,极易造成较大的变形.文中介绍了该类零件加工中一种行之有效的解决方案--柔性装夹.该柔性装夹工装是一件普通的外圆磨削心轴,在心轴根部的凹槽中放置了圆环状的弹性材料,用以衬紧工件,并提供工件旋转的驱动.通过该柔性装夹方式,在外圆磨床上实现了薄壁件端面的线性磨削,很好地降低了磨削热量的产生,充分冷却还提高了散热效果.某薄壁件的直径/厚度接近18,厚度4±0.01.在该磨削实例中,常规磨削的加工时间约为180分钟/件,合格率60%,而柔性装夹的加工时间约为12分钟/件,合格率98%,取得了非常不俗的实际磨削效果.     

Robotic drilling system for titanium structures

Manual drilling in titanium structures is a tedious and labor-intensive work. To reduce man-hour requirements while concurrently improving hole quality, we developed a robotic drilling system for this application. The lean system contains the product holding fixture, the industrial robot, the end effector, the control and sensor system, and the offline programming. The system functions include locating workpiece with a calibration stick or the vision system, weld mark inspection, one-sided clamping, drilling and reaming hole in material stack combinations of titanium and aluminum, and real-time thrust force feedback. The positional accuracy and the repeatability of the system have successfully been placed within the specification’s 0.3 mm tolerance and 0.2 mm tolerance, respectively. The dimensional accuracy of drilled holes in both Ti alloy and Al alloy materials is within H9 tolerance.     

离心力补偿卡盘高速回转夹紧特性研究

通过对高速切削过程中卡盘和工件的受力与变形分析，建立了离心力补偿卡盘夹紧力变化的理论分析计算模型，并进行了实验验证。研究了卡盘的实际夹紧力变化、离心力补偿效率、夹紧力迟滞等高速回转夹紧特性，指出了卡盘设计和使用中应注意的问题，为更加合理有效地发挥离心力补偿卡盘的高速潜能、提高高速车削过程的安全性提供了科学的技术依据。     

Analysis and comparison of laser cutting performance of solar float glass with different scanning modes

Cutting quality and efficiency have always been important indicators of glass laser cutting. Laser scanning modes have two kinds, namely, the spiral and concentric circle scanning modes. These modes can achieve high-performance hole cutting of thick solar float glass using a 532-nm nanosecond laser. The mechanism of the glass laser cutting under these two different scanning modes has been described. Several experiments are conducted to explore the effect of machining parameters on cutting efficiency and quality under these two scanning modes. Results indicate that compared with the spiral scanning mode, the minimum area of edge chipping (218340 µm²) and the minimum Ra (3.01 µm) in the concentric circle scanning mode are reduced by 9.4% and 16.4% respectively. Moreover, the best cutting efficiency scanning mode is 14.2% faster than that in the spiral scanning mode. The best parameter combination for the concentric circle scanning mode is as follows: Scanning speed: 2200 mm/s, number of inner circles: 6, and circle spacing: 0.05 mm. This parameter combination reduces the chipping area and sidewall surface roughness by 8.8% and 9.6% respectively at the same cutting efficiency compared with the best spiral processing parameters. The range of glass processing that can be achieved in the concentric circle scanning mode is wider than that in the spiral counterpart. The analyses of surface topography, white spots, microstructures, and sidewall surface element composition are also performed. The study concluded that the concentric circle scanning mode shows evident advantages in the performance of solar float glass hole cutting.     

大型深孔钻镗床的滚压加工

利用金属的塑性变形,使工件内孔达到尺寸精度和粗糙度要求,同时提高表面硬度和耐磨性。利用减小夹紧面积来进行工件找正。大型深孔钻镗床的滚压加工特别是对于大型油缸体的内孔加工具有很高价值。     

新型船用艉管轴承孔的加工工艺改进

船用艉管轴承毛坯是进口半成品,以内孔为基准,加工外圆成品。本文介绍了艉管轴承孔加工过程所采取的加工工艺方案,对使用的机床设备、定位基准和装夹方法的确定、夹具的设计、工艺参数的选择以及内孔尺寸公差的测量等进行了详细的工艺分析。     

伸出爪卡盘的受力分析与优化设计

根据安装在滚轮上大直径圆柱形工件进行表面处理的特点,设计了一种新型的伸出爪卡盘,并利用微调结构克服电动机主轴与工件轴心线偏差.经过对伸出爪卡盘受力分析,对其进行结构优化,利用限位销或定位槽机械定位作用,使伸出爪牢牢地卡住工件,顺利传递扭矩,完成工件的表面处理.     

动力卡盘动态夹紧力测试系统研制

为测量旋转状态下车床动力卡盘夹紧力,设计并制作了一套基于S型压力传感器的卡盘无线测力装置,该装置由传感器、变送器、数据存储及显示模块三部分组成.对传感器进行性能测试验证,并设计与制作了变送器实物.采用LabVIEW建立虚拟机,对采集到的信号进行存储及显示.实验测试结果表明:该系统可以满足动力卡盘夹紧力的测试需求.     

多规格汽车轮毂夹具设计

设计的夹具适合内孔直径在50 mm~17 mm区间变化的轮毂,符合我国无内胎汽车轮毂中心孔的尺寸范围变化大的实际情况。该夹具具有自动定心功能,定心精度高,结构简单,定心简便、可靠,夹紧力的大小可调,夹紧速度可控的特点,节省了劳动力,提高了工作效率,降低了成本。