细长杆车削系统的动力学建模

根据等截面梁的横向振动理论，建立细长杆系统横向自由振动的偏微分方程，求出细长杆的振型函数。当设定装夹情况为卡盘—顶尖装夹时，求得细长杆的一阶固有频率。从激励及切削力的分析知，切削力对细长杆的激励可简化为两个相互垂直的简谐力激励，此简谐力的频率就是细长杆的转速。所以，要减小细长杆车削中的振动，转速必须远离细长杆系统的一阶固有频率，即避免产生共振。     

变截面细长杆振动车削的试验研究

变截面细长杆振动车削的试验研究东北大学祝锡晶太行仪表厂祝锡亮华北工学院王纯一、前言变截面细长杆是指直径小于５０ｍｍ，长径比为１２－５０的轴类零件，在机械工业和国防工业及声学领域里有广泛的用途。目前我国许多厂矿对此类零件的加工一般仍沿用传统的工艺方法，...     

利用反馈磁场车削细长杆

由于车削细长杆工艺系统刚性较差，工件在切削力作用下易产生弯曲变形，导致实际切削深度发生变化，工件最终形成了鼓形误差。减小鼓形误差的关键在于减小工件的弯曲变形。目前，常用的跟刀架车削方法存在着以下弊端．1．跟刀架调整麻烦，辅助工时长，对操作工人的技术水平要求高。2．为保证银刀架工作正常，要求工件在前工序有较好的几何精度及表面质量。3．跟刀架支承快与工件接触，限制了工件转速的提高，影响工件表面质量及生产率。采用反馈磁场方法来车削细长杆具有以下优点．1．细长杆的交承方式，由接触式转化为非接触式，使工件转速…     

高速逆向车削细长轴

本文对加工细长轴正向切削和逆向切削时的受力和变形进行了分析，建立了在切削力作用下发生弯曲变形的力学模型，并对机床——工件——刀具组成的工艺系统进行综合优化组合，得出高速逆向切削细长轴可以提高轴的刚性，减少其弯曲变形，保证轴的加工精度的结论。     

细长杆件车削加工过程中的受力分析

随着科学技术的不断发展，特别是航天航空工业的发展对其零部件的要求越来越高，很多难加工材料制作的细长杆件就应运而生，传统的加工方式很难满足其加工精度和生产效率的要求。文中对细长杆件加工过程进行了静态、动态分析，剖析了在细长杆件加工过程中的静力学受力、自激振动等问题，特别对细长杆件加工过程中的自激振动进行了深入的分析。提出了研究和解决细长杆件加工过程中的振动问题的新思路。     

车削加工细长轴的工艺改进研究

分析了车床精度、刀具材料及结构、加工工艺、工件装夹方式、切削热及切削力等因素对细长轴加工精度的影响.通过正确选择刀具材料结构与几何参数,制定合理的工艺路线,采用三支承爪、中心架、跟刀架、弹性顶尖等合适的夹具与合理的安装方式,提高了细长轴的加工精度.     

如何顺利车削细长轴

文中针对车工考试、比赛过程中细长轴加工容易产生的问题,提出了解决方案,提高车削加工效率。     

100倍细长杆的车削

在卷纸管心轴的车削过程中，就遇到过细长杆类零件。此类零件批量小(一次只加工几件)且长径比近100倍，而且没有专用设备及专用夹辅具，只能用普通车床车削，给加工带来了很大困难。在生产中，我采用螺纹回转顶尖拉制切削，反向走刀两爪跟刀架，通过反复试制，加工出合格产品，解决了生产急需。     

细长多头内螺纹的车削

一、零件结构及其功能 图1所示为带细长多头内螺纹的精密导套,用于精密钻、扩、铰刀具的导向,借助左右螺旋槽,控制从中间空刀槽4个径向孔进入的切削液,只能流向刀具前端切削处。国外原设计内螺纹部分为硬质合金压制成形,目的一是具有高硬度而耐磨,二是工艺性好,     

Process monitoring in precision cylindrical traverse grinding of slender bar using acoustic emission technology

The precision cylindrical traverse grinding process of slender bar is very complex for the strongly time dependent properties of the wheel. Therefore, it is very difficult for operators to properly judge the grinding state using naked eyes and ears. This calls for automatic monitoring technology that can monitor the process in precision cylindrical traverse grinding to guarantee machining quality and productivity as well as reduction in cost. This study developed an automatic monitoring system for precision cylindrical traverse grinding of slender bar using Acoustic emission (AE) technology. Grinding tests on molybdenum were conducted under traverse conditions in a conventional cylindrical grinder. It was found that larger radial material removal depth results in larger root mean square value of Acoustic emission signals (AE_RMS). Based on this, the AE_RMS was analyzed and used to determine the finishing of spark-out process and the pre-processing of tool alignment. The variation tendency of AE_RMS in one spark-out process was applied to determine when a wheel wears out and has to be dressed. The experimental results showed that the AE system was effective to monitor the pre-processing of tool alignment, spark-out and wheel wear in precision cylindrical traverse grinding of slender bar.

     

细长轴车削刀具的设计

介绍了细长轴车削中存在的主要问题，对刀具的要求，并给出了应用实例。     

细长轴的双刀车削加工精度的研究

细长轴类零件刚性差,抗弯能力弱,在加工过程中容易产生弯曲变形.在总结现有加工方法的基础上,通过分析刀具切削力在轴上的分布,建立了双刀车削力学模型,用ANSYS有限元法对双刀车削的加工精度进行仿真分析,并通过双刀切削试验获取的数据,绘制细长轴的直径坐标曲线图,确认了双刀车削加工方法可以达到提高加工精度的目的.     

关于逆向车削加工细长轴误差的力学分析

针对细长轴车削加工，分别在两种不同装夹条件下(一端卡盘夹紧、一端顶尖支承和两端顶尖支承)进行正向切削和逆向切削时的工件变形进行了力学分析，建立了正逆向切削工件在切削力作用下产生弯曲变形的解析模型。具体算例表明：逆向切削时工件的弯曲变形以及由此引起的加工误差远小于同等条件下正向切削的变形和误差。该模型及分析结果可用于细长轴加工的工艺设计。     

超细长轴车削变形和工艺方法研究

超细长轴加工中产生的振动和变形直接影响加工的精度.理论上用有限元法分析采用不同装夹方法超细长轴加工变形.实践上采用不同的加工工艺,进行反复试验、并设计了新型拉紧夹具;能够有效地控制振动和变形,保证了加工精度,提高了加工效率.     

细长车削工件的精密夹持

当深孔镗杆长达12m时,夹持装置特别重要。高精度手动Rota-Splu车床卡盘能保证加工出高质量的工件,而且工作可靠。德国不锈钢产品制造商在细长产品制造和加工方面处于领先地位。Schmolz+Bickenbach集团公司是一家拥有4000职工的企业,每年要加工上百万吨的不锈钢。集团在Witten、Siegen、Krefeld和     

基于扭杆弹簧的水冲洗车翻转楼梯设计

根据地铁冲洗车上搬运和安放辅助小车的具体任务,设计一种可翻转的楼梯来满足所需的要求。通过力学分析,设计一种扭杆弹簧用于楼梯的翻转,该扭杆弹簧可使楼梯翻转至水平状态时,其扭力矩与楼梯和小车产生的重力矩保持平衡。在翻转过程中,扭杆的弹性势能与楼梯的自重势能相互转换,可在很大程度上减小人工推力,降低操作者的劳动强度。     

大型圆柱滚子车加工方法改进

在详细分析原有大型圆柱滚子车加工方法不足之处的基础上，提出了切实可行的改进方法，大大减少了加工工序，提高了产品质量和加工效率，减少了钢材浪费。     

An experimental investigation of cylindrical wire electrical discharge turning process

The cylindrical wire electrical discharge turning (CWEDT) process was developed to generate precise cylindrical forms on hard, difficult to machine materials. A precise, flexible, and corrosion-resistant submerged rotary spindle was designed and added to a conventional five-axis CNC wire electrical discharge machine (EDM) to enable the generation of free-form cylindrical geometries. The hardness and strength of the work material are no longer the dominating factors that affect the tool wear and hinder the machining process. In this study, the effect of machining parameters on surface roughness (R _a) and roundness in cylindrical CWEDT of a AISI D3 tool steel is investigated. The selection of this material was made taking into account its wide range of applications in tools, dies, and molds and in industries such as punching, tapping, reaming, and so on in cylindrical forms. Surface roughness and roundness are chosen as two of the machining performances to verify the process. In addition, power, pulse off-time, voltage, and spindle rotational speed are adopted for evaluation by full factorial design of experiments. In this case, a 2²?×?3² mixed full factorial design has been selected considering the number of factors used in the present study. The main effects of factors and interactions were considered in this paper, and regression equations were derived using response surface methodology. Finally, the surfaces of the CWEDT parts were examined using scanning electron microscopy (SEM) to identify the macro-ridges and craters on the surface. Cross sections of the EDM parts were examined using the SEM and microhardness tests to quantify the sub-surface recast layers and heat-affected zones under specific process parameters.