提高宽厚板定尺剪剪切精度的措施

主要介绍了莱钢宽厚板定尺剪的结构和组成,以及主要剪切缺陷的产生原因。分析了影响定尺剪剪切精度的主要因素,并提出了提高定尺剪剪切精度的策略。经过改进后,定尺剪剪切误差控制在1‰以内。     

小型棒材线优化剪切短尺轧件分离技术新方案

介绍了小型棒材轧钢生产线上优化剪切短尺轧件分离技术的剪切数学模型,对比分析了人工设定倍尺剪剪切长度、定尺剪后短尺轧件集中分离,自动设定倍尺剪剪切长度、定尺剪后短尺轧件集中分离,以及倍尺剪后进行短尺轧件分离这3种分离方案的优缺点。     

角钢飞剪机

1.概述在现代轧钢生产线上,轧制速度不断提高,成品轧件不断加长,因此,飞剪机将得到越来越广泛的应用。目前,型钢生产线上使用的双剪刃作平面平行运动的飞剪机,在切头、切尾和定尺剪切时采用以下3种工作方式: ①起动工作制下完成剪切。这种方式的缺点是剪切速度低、定尺精度差。用于切头较好。在切定尺、倍尺或切尾时,要求剪刃旋转1周(或1周稍多些)完成起动、剪切、制动。由于运动机构转动惯量大(含电机),     

第1台国产滚切式定尺剪试车成功

我国自行开发设计并制造的第１台国产双轴传动滚切式定尺剪于３月２８日在中国第二重型机械集团公司一次负荷试车成功这台由第二重型机械集团公司自己开发设计并制造的中厚板滚切式定尺剪，可剪切钢板厚度４～４０ｍｍ、板宽２３００ｍｍ、钢板强度８００ＭＰａ（板厚４０ｍｍ时）、最大剪切力达９０００ｋＮ，剪切次数１７次／ｍｉｎ。这台剪机的设计制造成功，改变了我国过去依赖进口的局面，填补了国产滚切式定尺剪空白。该产品与传统的斜刃剪比较，具有剪切钢板质量好，剪切次数高，能快速更换剪刃，能自动调整剪刃间隙，剪切钢板自动剪…     

定尺剪剪切效率和质量的影响因素分析

简述了滚切式定尺剪的设备组成、剪切过程和性能参数 ,对影响剪切生产率和剪切质量的因素进行了分析     

螺旋剪刃滚筒飞剪的设计研究

结合北方重工集团有限公司设计的滚筒飞剪机,介绍了螺旋式剪刃的滚筒飞剪的剪切原理,并对滚筒飞剪力能参数进行计算。该滚筒飞剪采用电机通过膜片式联轴器驱动齿轮轴,具有主副齿结构的传动方式;采用螺旋式剪刃进行剪切。生产实践表明,定尺长度精度可控制在±0.5 mm以内。     

圆盘剪和滚切式定尺剪的剪切缺陷及防止措施

分析了中板生产中圆盘剪和滚切式定尺剪的剪切缺陷及形成原因,并提出了相应的解决办法.     

单轴双偏心定尺滚切剪运动轨迹求解及计算机仿真

根据单轴双偏心定尺滚切剪机构运动学分析,给出了机构运动轨迹的三维非线性方程,确定了在曲轴带动下任意时刻剪切机构各铰接点坐标,实现了对定尺滚切剪滚切过程的计算机模拟,为滚切剪设备的设计制造提供了一定的参考依据.     

滚切式双边剪和定尺剪剪刃间隙调整公式探讨

对滚切式双边剪和定尺剪剪切钢板时剪刃间隙如何选择进行了分析。为保证钢板剪切质量、延长刀片使用寿命,结合韶钢二轧厂实践,对其剪刃间隙调整的经验公式进行了探讨。     

对小型精整工艺改革必要性的看法

现有小型棒材轧机的成品轧件均先借助于摆槽飞剪、双滚筒式飞剪或启动式飞剪。大体剪成数根长的冷床定尺(倍尺),或不经剪切直接进入冷床冷却。然后通过冷剪成批地,几根至几十根地剪头、剪定尺、非定尺,再剪尾,经辊道送至检验台架,经检验后包装、过磅、入库。     

宽厚板轮廓检测及智能剪切系统核心技术

宽厚板剪切线操作复杂,多数情况需要工人目测并结合生产经验判断母板长度、侧弯大小和切头位置,容易导致短尺和粗分错误等现象。为此,研发了一套宽厚板轮廓检测及智能剪切系统,可对宽厚板进行轮廓检测,消除了钢板运动过程中板身震动对检测精度的影响。介绍了该系统智能剪切模型,分析了钢板最大有效长度和侧弯量等指标,以此为基础制定智能剪切策略,并优化切头剪操作。应用效果表明,该系统正常运行率达到99.8%以上,钢板宽度检测精度±3 mm,长度检测精度±30 mm,侧弯检测精度±3 mm,粗分准确率达95%以上,达到了智能剪切的目的,提高了剪切线的生产效率。     

剪板机同步剪切伺服控制探析

目前的板料剪切生产线中,板料是按一定的速度向前进行输送而不能停止下来由剪切装置对钢板进行剪切,大多只能采用简单的旋转切的方法剪切板料,从而对板料在切口处造成伤害,影响产品的表面质量。应用Lenze交流伺服控制器,可实现剪板机的同步剪切控制,进而能够有效降低负载冲击,提高系统稳定程度,提高剪切精度。     

板材剪切与冲裁加工实验的位移测量系统

针对板材剪切与冲裁加工的特点，设计了一种应变片式位移传感器。传感器可根据需要对量程进行调节，且相对精度不变，特别适于中小位移的测量。结合数据采集系统，在材料试验机上实现了板材剪切加工和精密冲裁实验的位移测量。     

An analytical force model with shearing and ploughing mechanisms for end milling

An analytical force model with both shearing and ploughing mechanisms is established for the end milling processes. The elemental forces are defined as the linear combination of shearing and ploughing forces in six cutting constants. The analytical model for the total milling forces in the angular and frequency domain are derived by convolution approach and Fourier transform respectively and are expressed as the superposition of the shearing force component and ploughing force component. This dual-mechanism model is analyzed and discussed in the frequency domain and compared with the lumped shear model. An expression is derived for identifying the cutting constants of the dual-mechanism model from the average milling forces. Explicit inclusion of ploughing force in the model is shown to result in better predictive accuracy and yields a linear force model with constant cutting coefficients. Experiments verify the accuracy and the frequency analysis of the dual-mechanism model and show that cutting constants for the dual-mechanism model are fairly independent of chip thickness.     

Identification of shearing and ploughing cutting constants from average forces in ball-end milling

This paper presents an analytical model for the direct identification of global shearing and ploughing cutting constants from measured average cutting forces in ball-end milling. This model is based on the linear decomposition of elemental local cutting forces into a shearing component and a ploughing component. Then, a convolution integral approach is used to obtain the average cutting forces leading to a concise and explicit expression for the global shearing and ploughing cutting constants in terms of axial depth of cut, cutter radius and average milling forces. The model is verified by comparisons with an existing force model of variable cutting coefficients. Cutting constants are identified through milling experiments and the prediction of cutting forces from identified cutting constants coincides with the experimental measurements. A model for identifying the lumped shearing constants is obtained as a subset of the presented dual mechanism model. Experimental results indicate that a model with dual-mechanism cutting constants predicts the ball-end milling forces with better accuracy than the lumped force model.     

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。     

异周速双滚筒切头飞剪结构特点及分析

介绍了从日本引进的异周速双滚筒切头飞剪的技术参数、工作原理、主要结构特点,对剪切过程及剪切质量进行了描述;应用力学原理,分析了剪切过程中滚筒组的扭转变形规律,相应的刀刃侧隙沿滚筒轴线变化特点,M-T齿轮对的功用,分配齿轮和M-T齿轮所具有的正变位、短齿、齿向修形结构特点。讨论了刀刃侧隙的确定方法。分析表明,M-T齿轮对的应用更加可靠地保证了无侧隙啮合传动,大幅度地提高了剪切刚度;可采用较小齿侧间隙又不过高地提高齿轮加工精度和装配精度,并有效地改善了载荷分布。     

Identification of cutter offset in end milling without a prior knowledge of cutting coefficients

This paper presents a method for the identification of cutter offset through milling force without requiring the specific cutting coefficients to be known as priori. The total milling force in the presence of cutter offset is first obtained on the basis of dual cutting mechanisms, where the local force is comprised of a constant plowing force and a linear shearing force proportional to the chip load under the cutter offset. The total milling force is synthesized through convolution and is shown to be the sum of three force components: the nominal chip shearing force component, the plowing force components and the offset related shearing force component. Fourier analysis of these force components reveals the effects of offset geometry and yields formulas for the identification of offset geometry. The identification process requires only two cutting tests and the evaluation of two algebraic expressions; the shearing constants are found from the average forces of cutting tests and the offset geometry is identified from the force component at the spindle frequency. Through numerical simulation and experimental results, the efficacy of the identification method is demonstrated; the effects of feed per tooth and cutting depths on the accuracy of the model are investigated and criteria for the appropriate selection of these parameters are suggested.     

新一代液压滚切剪技术的研究及应用

为提高中厚板的剪切质量,降低设备成本,提出了一种PR-8R-PR杆系的剪切机构,该机构将左右两台液压缸与机架铰接,液压缸推动连杆,使其带动机架运动,完成剪切。控制系统采用带检测反馈的双闭环控制,精度高,稳定性好。剪切后切口断面毛刺≤0.5mm,断面垂直度90°±1°,钢板边部瓢曲度≤0.15mm/m。