棒料径向夹紧精密剪切模

通过研究剪切模具对棒料剪切质量的影响因素,设计了一种适用于普通冲床的棒料精密剪切模具,该模具通过弹簧提供径向夹紧力,且径向夹紧机构与剪切刀具设在同一模具上.模具能够提高棒料剪切断面质量及下料效率,节约了生产成本.     

分力夹紧棒料剪切装置

<正> 传统下料中,棒料一般都是借助于各种锯床或剪切机、冲床来下料的。近年来,国内外不少人开始研究棒料下料工艺,新的精密剪切机也相应问世,但设备投资较大,本文旨在推出一种新的下料方法——分力夹紧剪切装置,只要利用普通冲床即可对各种棒料进行精密剪切下料。     

棒料剪切机理与提高剪切精度的方法

从一种新的角度对棒料剪切下料时的变形机理进行了分析研究，指出了影响被剪毛坯断面质量的主要因素，并且介绍了相应的解决方法。本还提出了一种对剪切下料中由于热轧棒料直径公差所造成的被剪毛坯体积公差进行自动补偿的机构。     

浙江机电职业技术学院机械工程学院

针对传统棒料剪切设备存在的较差的断面剪切质量和较低的剪切效率、材料利用率,分析影响坯料剪切断面质量的主要原因,研究径向夹紧和高速剪切组合的棒料精密剪切下料工艺。同时设计棒料精密剪切设备,对设备的原理、结构和控制系统进行了分析。结果表明：开发的精密棒料剪切设备,剪切后坯料的断面倾斜度、椭圆度和粗糙度明显小于普通剪切,获得了较高的断面剪切质量、效率和材料利用率。     

液气棒料精密剪切机设计研究

在棒料精密剪切理论的基础上研究设计了一台新型的4kJ液气棒料精密剪切机。通过对剪切机结构形式等若干问题的分析和讨论,以期促进棒料精密下料新工艺、新技术的发展。     

棒料剪切模刀板失效对锻造成形的影响

棒料剪切下料是锻造生产的首道工序，下料质量的优劣直接影响了后道锻造成形工序的质量，特别是精密成形工艺对坯料的质量要求更高，常用的剪切模下料不能满足其对坯料重量和外观质量的要求。本对常用的剪切模刀板的失效原因进行了分析，并提出了一些防止措施。     

基于夹紧状态的棒料高速精密剪切机理及试验研究

结合断裂力学中的线弹性断裂理论关于Ⅱ型裂纹裂尖塑性区域尺寸的研究,深入探讨了夹紧状态下的棒料高速精密剪切机理,得出高速精密剪切的实质是实现裂尖塑性小范围屈服。在理论研究基础上,分析了各剪切工艺参数对剪切断面质量的影响,并利用试验样机对棒料高速精密剪切进行了试验。结果表明,与普通剪切方法相比,基于夹紧状态下的高速剪切可获得满意的断面质量。     

液气棒料精密剪切机设计研究

在棒料精密剪切理论的基础上研究设计了一台新型的4kJ液气棒料精密剪切机。通过对剪切机结构形式等若干问题的分析和讨论，以期促进棒料精密下料新工艺、新技术的发展。     

沈阳求实 求精务实 开拓创新

背压式精密剪切下料,简称精密剪切下料,其原理是棒料剪切时在剪下端施加一个足够大的背压力,使被剪棒料只能沿着滑块运动方向平行移动,而不产生弯曲,这样得到的坯料精度很高。而且精密剪切属于无屑下料,没有切口损耗,有着节材环保的优点,此外,还能做到高效节能。     

剪切下料过程分析及提高毛坯断面质量的途径

从一种 角度对棒料剪切下料时的变形机理进行了分析研究，指出了影响被剪毛坯断面质量的主要因素，并提出了相应的解决方法。     

莱钢特钢棒材冷剪的技术改造

针对莱芜钢铁集团公司特殊钢厂小型车间原有的4000kN冷剪存在的铸造框架多处开裂、箱体刚度低、剪切能力低等问题,通过将壳体“C”型结构改为龙门框架结构,采用40Cr铸造;用定位销取代方键;将剪头提升销直径由φ35mm增大到φ50mm,并对滑架加装碟簧缓冲装置;曲轴装配采用膨胀套无键连接,降低了设备故障率,提高了剪切质量和剪切效率.     

Recent developments of shearing in Japan

In this article, leading research and development activities of shearing in Japan are reviewed. Main contents are elucidation of shearing mechanism, theoretical analysis, tool life, burr-free blanking, precision shearing, bar cropping, pipe cutting, slitting, shearing of non-metallic materials, tool making, shearing of extremely thin sheets, etc.     

同周速飞剪与异周速飞剪力能参数对比研究

介绍了断裂理论及断裂准则(Normalized CockcroftLatham),同时运用有限元软件DE-FORM-2D对异周速滚筒式飞剪动态剪切过程进行模拟,对比了同周速飞剪和异周速飞剪剪切力、剪切功、侧推力及剪切扭矩等力能参数的差异,对比分析了两种剪切方式下剪切断面质量,为滚筒式飞剪剪切理论研究提供了一定的依据。     

金属板材无毛刺精密分切新工艺分切断面形貌特征

基于负间隙冲裁加工原理,针对圆盘剪纵向分切加工,通过分析控制分切过程的材料应力状态,将分切过程分解为塑性剪切和压迫分离两个阶段,提出金属板材无毛刺精密分切新方法,即塑性剪切压迫分离精密分切工艺。采用镀锌板对无毛刺精密分切新工艺加工过程进行实验研究,分析塑性剪切压迫分离精密分切材料变形过程及板材受力特点;通过显微形貌观察,研究无毛刺精密分切新工艺分切断面的双塌角、双剪切区、中部剪切断裂区的形貌特征,并与传统圆盘剪分切工艺的分切断面特征进行对比。结果表明,采用塑性剪切压迫分离精密分切新工艺,可以消除分切毛刺从而提高金属带材的质量。     

High-speed machining of titanium alloys using the driven rotary tool

Machining of titanium at high cutting speeds such as from 4 m/s to 8 m/s is very challenging. In this paper, a new generation of driven rotary lathe tool was developed for high-speed machining of a titanium alloy, Ti–6Al–4V. The rotary tool was designed and fabricated based on the requirements of compact structure, sufficient stiffness and minimal edge runout. Cylindrical turning experiments were conducted using the driven rotary tool (DRT) and a stationary cutting tool with the same insert, for comparison in the high-speed machining of Ti–6Al–4V. The results showed that the DRT can significantly increase tool life. Increase in tool life of more than 60 times was achieved under certain conditions. The effects of the rotational speed of the insert were also investigated experimentally. Cutting forces were found to decline slightly with increase of the rotational speed. Tool wear appears to increase with the rotational speed in a certain speed range.     

数据线壳多工位级进模设计

经过多次切边、4次普通拉深、镦R角、3次变薄拉深、冲孔和旋切落料等15个工序,在一套多工位级进模中实现了铝合金数据线壳零件的生产。采用经验值加软件仿真的方式获得拉深下料的外形尺寸。排样方案采用42 mm宽的条料,由自动送料机自动送料,42个Ф2.5 mm的导正销精定位,送料步距为32 mm。详细介绍了变薄拉深工位和旋切落料工位的结构设计,3次变薄拉深的变薄量分别为0.05,0.03和0.02 mm,变薄系数分别为0.88,0.91和0.94。为确保运动精度,模具设置了20对内导柱和内导套,且关键零件均设计成镶拼结构。通过实际生产验证,该模具生产的产品质量稳定,生产效率高。     

Identification and compensation of systematic deviations particular to 5-axis machining centers

This paper presents an algorithm for identifying particular deviations such as angular deviations around linear axes relating to rotary axes in 5-axis machining centers. In this study, three kinds of simultaneous three-axis control motions are designed for each rotary axis to identify the deviations. In the measurement, two translational axes and one rotary axis are simultaneously controlled keeping the distance between a tool and a worktable constant. Telescoping ball bar is an effective instrument for measuring the relative displacement to the reference length in the work volume because its attitude is freely changed. In these three-axis control motions, the sensitive direction of the ball bar is kept constant. In order to determine the deviations, we derive eight equations from the relationship between the eccentricities obtained from the measured circular trajectories and the approximations derived from the mathematical model based on the simulation. In the simulation, a mathematical model considering the particular deviations is developed and then the characteristic diagrams are prepared for every deviation and every three-axis control motion. Based on the results, we propose a procedure for identifying the particular deviations in 5-axis machining centers and its procedure has been applied to identify the deviations actually. From both the simulation and the experiment, it has been confirmed that the proposed method gives precision results and is able to apply to the measurement of 5-axis machining center which is a tilting rotary table type.     

A model for cutting forces generated during machining with self-propelled rotary tools

In this paper, a force model for self-propelled rotary tool is presented. Conventional oblique cutting force predictions were reviewed and extended to predict the cutting forces generated during machining with the self-propelled rotary tools. The model presented is based on Oxley's analysis and was verified by cutting tests using a typical self-propelled tool. Good agreement was obtained between the predicted and the experimentally measured forces under a wide range of cutting conditions. The effect of different cutting conditions on the friction coefficient along the chip/tool interface and tool rake face normal force were also presented and discussed.     

圆钢径向夹紧精密剪切模设计

介绍了一种用在通用冲床上的径向夹紧圆钢剪切模的结构、工作原理和设计制造要点。该剪切模是在圆钢处于径向夹紧和受压状态下切断圆钢,使剪切断面与圆钢轴线垂直,剪切面变形很小,断面光滑平整。该模具工作可靠,切料质量高。     

预偏角精密棒料剪断机

介绍了新研制的Q4 5-50W型预偏角精密棒料剪断机的工作原理、结构和性能特点 ,以及工艺实验效果。