镗杆和镗套烧结咬死的解决方法

在生产实践过程中,从镗杆镗套烧结咬死后修复的角度有针对性地提出了几种快速、适用的修复方法.并对镗杆和镗套的结构进行了大胆的改革,这些方法已经过多次生产实际验证,有效地解决镗杆和镗套易烧结的问题,保证复合镗床在使用过程中不会因机床维修而长期影响生产.     

镗杆与镗套烧结原因分析及预防措施

详细分析了镗杆与镗套烧结的原因,并有针对性的提出了多种防止烧结的措施,采取这些措施后可避免烧结的各种诱因发生,是解决镗杆和镗套易"烧结"问题的有效方法.     

FBT190/320落地镗铣床镗杆、镗套的修复工艺设计

镗杆是镗床中主要零件之一,生产中长期使用后磨损严重,直接影响镗床的加工精度.而新换一根新镗杆的价格昂贵,故生产中常采用修复镗杆副主要零件(镗杆、镗杆套、调整轴承)的方法来恢复其加工精度.     

镗杆与镗套之间允许间隙极限值的探讨

镗杆与镗套之间的间隙直接影响被加工孔系的加工精度。文章对如何确定镗杆与镗套之间的允许间隙极限值进行探讨。     

修复淬硬镗杆中的孔加工

我厂一台T617镗床的镗杆,在长期使用中装夹刀具的部位严重研损(见图1)不能自锁。故决定修复,方案为载短80mm后重新加工内锥孔和方孔。     

快速镗槽刀杆

在台钻主轴箱上,有如图1所示的两个弹簧卡槽.在开始生产时,我们在C630车床上车制,工人的劳动强度大,而且生产效率也很低,为此,我们设计了可在钻床上使用的快速镗槽刀杆,不但极大地减轻了工人的劳动强度,而且提高效率3～4倍,并提高了质量.1.结构及原理     

减小镗杆颤振的方法

镗杆折悬臂结构决定在镗削时不可避免地产生颤振，颤振降低加工工件的表面质量及几何精度；减小颤振是镗杆设计的重要课题；文中介绍了利用动力吸振器、冲击消振器、调整切削参数等方法减小颤振；并介绍根据这些方法设计的镗杆。     

一种新型抗振镗杆的结构设计

针对镗杆在加工过程中的振动问题,结合碰撞减振理论及复合层叠材料力学原理,设计出了一套新型抗振镗杆。镗杆中装有的减振装置及复合层叠结构,能有效地降低在镗削过程中镗杆的振动性,为金属高精加工提供了有力的技术保障,有一定的理论意义和实用价值。     

偏心微调镗杆的设计和计算 （下）

三、设计参数的确定 1.刻度值的计算偏心微调镗杆刻度盘上刻度数的多少取决于被加工孔的尺寸精度和工人操作的熟练程度。刻度值的计算一般可分为两步进行。 (1)已知镗杆偏心量e和镗刀杆自转每一刻度后切削半径ρ的增量δ,求需要刻出的格数n。由偏心微调刀杆的工作原理可知,在镗刀杆自转角θ=O→π的范围内,切削半径ρ的最大增量ρ△_(mac)=2e。在此区间若在刻度盘上刻出n格的刻线,则镗刀杆自转过n格后,刀尖切削半径的增量为nδ,即nδ=2e     

刀头位置可调的阶梯孔精镗镗杆

介绍了一种刀头配置角度可调的阶梯孔镗杆,这种镗杆可根据被加工材料调整两刀头相对位置,刚性好,镗削精度高,且能提高镗削效率。     

圆柱十字滑块零件加工工艺安排及镗孔夹具设计

分析零件的工艺技术要求,制定了合理的工艺路线。阐述了镗模的设计内容,类型选择,定位及定位元件设计,镗套和衬套设计,镗模板和夹具体设计,夹紧装置设计,镗杆设计等。解决了精度低机床加工高精度零件的问题。     

Experimental analysis of boring process on automotive engine cylinders

In this article, mechanics of boring process on cast iron automotive engine cylinders is explored experimentally. In order to shorten the boring cycle time and to improve quality of the cylinder holes, effects of various cutting conditions as spindle speed, feedrate, inserts, and coatings are investigated. Real-time cutting forces are measured with dynamometer during the process. Surface roughness on the engine cylinders, flank, and crater tool wears are measured and compared in various cutting conditions. It is concluded that by selecting proper cutting conditions, cutting forces can be controlled below a threshold value, cycle time can be shortened, tool life and part quality can be increased; therefore, the cost of automotive engine boring process can be reduced significantly.     

深孔镗杆在推镗和拉镗时的ANSYS受力分析

深孔镗削是提高深孔加工精度的一种方法,它能校正己有孔上的缺陷,如圆度误差、直线度误差,从而获得良好的几何精度和表面粗糙度。深孔镗削的加工方式、运动形式、镗刀的轨迹方程和对镗削的受力分析是深孔镗削加工中各不稳定因素的渊源,在深孔镗削过程中,运用合适的镗削方式可以减小切削系统的振动。针对多刃均布式深孔镗刀,在推镗和拉镗方式下进行受力分析,并利用PRO/E建立镗杆几何模型并生成中性几何文件,通过ANSYS有限元法,计算出推镗和拉镗时镗杆产生的挠度以及最大应力应变曲线,将二者结果进行比较,证明在细长管时拉镗加工的优势。     

基于TRIZ理论的数控镗铣床主轴松拉刀系统分析与优化

为了降低松拉刀力对数控机床主轴系统的影响,提高主轴使用寿命,对数控镗铣床主轴松拉刀系统进行分析与优化。首先,针对数控镗铣床主轴松拉刀机构进行了分析设计,并建立了三维模型;其次,研究了主轴在松刀和拉刀两种状态的受力情况,得到了对主轴轴承寿命影响较大的为松刀力。最后,采用TRIZ理论对主轴松拉刀系统进行优化。研究结果表明,该优化在不降低松拉刀力的前提下确实降低了松拉刀力对主轴系统的影响。     

镗床加工大型静压轴承轴瓦座内球面的工装设计

静压轴承轴瓦座磨损严重,需加工处理,为此设计一套大型工装。该工装采用主轴带动镗套和镗杆及刀杆的结构来完成球面加工的切削运动,已取得了良好的使用效果。     

T68卧式镗床镗轴轴向窜动的故障分析与改造

T68卧式镗床镗轴轴向窜动产生于镗轴运转时的传动链各配合件的配合间隙。该配合间隙随着传动磨合时间的增加而增大,当超过设计制造允许值时将导致镗轴轴向窜动故障,使镗轴在铣削工件平面时平面度超差。具有明显故障特征的配合件有轴承与丝杠、滑座螺母与丝杠、滑座螺母内外组合体、传动啮合齿轮等。通过改造镗轴滑座螺母与丝杠不能自锁的锁紧机构装置,控制滑座位移,即在滑座导轨压板上加装压板,用螺钉紧固,将滑座与尾部箱体连成一体,故障排除,彻底解决了镗轴铣削工件平面平面度超差的问题。     

Parameter optimization of time-varying stiffness method for chatter suppression based on magnetorheological fluid-controlled boring bar

An innovative chatter suppression method based on a magnetorheological (MR) fluid-controlled boring bar for chatter suppression is developed. The MR fluid, which can change stiffness consecutively by varying the strength of the applied magnetic field, was applied to adjust the stiffness of the boring bar and suppress chatter. The cutting dynamic stability under different natural frequencies of the structure was analyzed by an energy method, which shows that cutting dynamic stability depends on both the natural frequency of the structure and the spindle speed. The chatter suppression mechanism with varying natural frequency is analyzed for further parameter optimization. Furthermore, both theoretical analyses and numerical simulations indicate that a square wave exciting current with a large amplitude and a moderate frequency has a better effect on regenerative chatter suppression. Experiments utilizing a MR fluid-controlled boring bar under an exciting current with different waveforms and frequencies were conducted. The experimental results show that the chatter can be significantly suppressed using MR fluid-controlled boring bar under a square wave exciting current with a frequency of 4–6 Hz and an amplitude of 0–2 A.     

调头镗孔工件与刀具装夹位置的合理确定

本文以提高同轴度为目的，推导出在调头镗孔时，工件固定于工作台上，工作台固定于床身上（刀具进给时）以及装夹刀具之镗轴伸出（工件进给时）的最佳位置。     

Feature signature prediction of a boring process using neural network modeling with confidence bounds

Prediction of machine tool failure has been very important in modern metal cutting operations in order to meet the growing demand for product quality and cost reduction. This paper presents the study of building a neural network model for predicting the behavior of a boring process during its full life cycle. This prediction is achieved by the fusion of the predictions of three principal components extracted as features from the joint time–frequency distributions of energy of the spindle loads observed during the boring process. Furthermore, prediction uncertainty is assessed using nonlinear regression in order to quantify the errors associated with the prediction. The results show that the implemented Elman recurrent neural network is a viable method for the prediction of the feature behavior of the boring process, and that the constructed confidence bounds provide information crucial for subsequent maintenance decision making based on the predicted cutting tool degradation.NSF Industry/University Cooperative Research Center (NSF I/UCRC) forIntelligent Maintenance Systems(IMS).