气缸套外圆平行度检测器

气缸套外圆平行度检测器我厂加工内燃机干式铸铁气缸套，工艺要求外圆表面素线对中心线的平行度为０．０１２５ｍｍ，由于气缸套较薄，变形量大，用常规方法检测误差很大。为此，我们设计了一种气缸套外圆平行度检测器，基本上消除了常规检测方法产生的误差，达到了检测要...     

干式气缸套外圆无心磨削加工浅析

外圆无心磨削是工件不定心的磨削,是一种适应大批量生产的高效率磨削方法。在干式气缸套生产线上,采用外圆无心磨削来加工气缸套的外圆直径也是一种比较先进的工艺措施。本文根据多年的生产经验和实际情况,对干式气缸套外圆无心磨削的加工原理,外圆直径的成圆过程,导轮曲面及修整和无心磨削加工的产品质量与控制等方面透行分析探讨。     

干式气缸套外圆无心磨削

干式气缸套外圆直径是在外圆无心磨床上加工的。在磨削过程中,将干式气缸套(图1)置于砂轮、导轮和托板三者之间。干式气缸套中心不定,其位置变化大小取决于粗磨前的原始误差。经过无心磨削后气缸套的外圆直径精度可达IT5～IT7级。圆度误差可达0.005～0.015mm,表面粗糙度值可达R_α0.8～0.2μm。     

提高缸套支承肩外圆端面位置精度

我厂加工的内燃机干式铸铁气缸套,肩台工序加工的尺寸见图1,在C620车床上加工缸套支承肩外圆宽度,使用弹性套筒夹具,用尾座顶尖顶着弹性套筒加工工件。由于工件壁薄只有1.5mm,顶尖力大工件易变形和产生裂纹,加工后的气缸套支承肩外圆端面跳动达不到工艺要求,为此我们设计了液性塑料夹具,解决了上述问题。 1.设计原理 干式铸铁气缸套支承肩外圆端面跳动公差要求是以缸套外圆中心线为基准。而实际加工是以缸套内圆     

薄壁高强度钢质气缸套珩抛工艺研究

在对超精加工工艺原理进行分析的基础上,通过某柴油机气缸套内孔超精加工试验,对其关键技术进行了创新性研究,并提出了＂珩抛＂的新概念。经过工艺试验及柴油机台架考核试验证明,＂珩抛＂处理后的气缸套,其内孔表面质量、耐磨性等综合性能明显优于用其它工艺方法加工的气缸套。     

镗轴外圆的超精加工

提出了对镗轴的外圆的精加工采用了精磨－超精加工的方法，并介绍了超精加工磨头，及工艺参数。     

粗车活塞外圆的夹具

在加工空压机活塞时,粗车外圆的质量会直接影响精加工的质量。为此,我们改进了夹具,可使活塞在一次装夹中,完成外圆的粗、精加工。     

蛇腹套弹性夹具

介绍加工干式气缸套外圆用的蛇腹套弹性自动定心夹具,阐述了这种夹具的设计原理,参数的选择以及主要零件的制造工艺方法。实践表明,在干式气缸套生产加工线上,使用蛇腹套弹性自动定心夹具,提高了干式气缸套的加工精度。     

外圆精密检测器在气缸套检测中的应用

为了提高发动机气缸套上、下环带的检测效率及准确性,利用浮标式气动量仪把被测量的尺寸转换为相应的空气流量变化的工作原理,设计了一种外圆精密检测器,解决了气缸套上、下环带的检测精度及效率问题,同时很直观的目测可以判断出对气缸套上、下环带的圆度、圆柱度、锥度、椭圆点等。     

气缸套支撑肩端面圆跳动检具

介绍内燃机气缸套支撑肩端面圆跳动的基准选择，结合气缸套的生产特点，介绍一种以气缸套上、下腰带外圆中心为基准测量支撑肩端面圆跳动的通用、可调式检具。     

机械自紧工艺控制参量的实验研究

机械自紧技术在超高压容器和身管制造过程中得到广泛采用,但国内尚无完整的设计方法和工艺规范。采用实验方法来研究机械自紧问题,设计了自紧冲头,搭建由液压泵站提供动力的机械自紧实验装置,建立应变、冲头行程及推力测量系统。对厚壁圆筒试件进行机械自紧实验后,获得了冲头挤进过程中推力的变化数据,结合实验结果和经验公式归纳了机械自紧冲头推力计算公式,得到的推力与实验测量值的误差在±10%以内。测量了机械自紧过程中的重要工艺控制参量外表面应变、残余应变和冲头位移-外表面应变曲线。机械自紧后进行稳定化、机械加工对再屈服压力影响的实验。     

大直径外圆滚压器的设计

介绍了加工大直径空心圆柱体外表面的专用滚压器的设计及应用，该滚压器可与外圆精车配套使用，使外圆表面的精车、滚压一次完成，可提高生产效率和保证加工质量。     

中大型深沟球轴承外圈沟道精仿工艺

仿形车床C7232原来用于中型深沟球轴承外圈沟道的粗加工,精加工由成型车刀完成。由于产品转型,加工直径变为φ250mm～φ320mm之间,沟道变宽使切削力增加,精车工序无法由成型刀完成。针对以上问题,用C7232车床进行精车试验,圆满完成中大型产品外沟道精加工,质量符合要求。     

MACHINABILITY STUDY OF CARBON/PEEK COMPOSITES

Composites are generally fabricated to near nett-shape, however, there is often a need to conduct some additional machining operations such as trimming of the edges. High tool wear and the need for good surface finish are some of the major concerns in machining. This study deals with the machining of Carbon/PEEK, a high performance thermoplastic matrix composite, which is being used extensively in aerospace industries because it is light and posses high specific properties compared to conventional metallic materials. The technique of the full factorial design of experiment is used to investigate the relative effects of the various machining parameters on the amount of tool wear and the surface quality of the workpiece.

Experimental results show that the cutting speed, depth of cut and feed-rate are the main factors that contribute to tool wear of the inserts. The surface finish is found to be independent of the machining parameters and much better than those obtained in the conventional machining of metals provided a critical cutting speed is exceeded. This critical cutting speed is found to be in the range of 70m/min to 75m/min. The cutting point temperature at this speed is found to have exceeded the glass transition temperature of the material, indicating that cutting is done in the rubbery regime. This leads us to conclude that the smooth surface finish of the workpiece is caused by some form of polymer softening action rather than determined by the tool geometry of the cutter.     

磁场电化学磁粒复合光整加工实验研究

开发出一种新的光整加工工艺－磁场电化学磁粒复合光整加工。研究了磁场环境下离子运动轨迹方程,分析了复合光整加工的原理并进行了相应的实验,由于洛仑兹力和电场力的综合作用,改变了离子运动轨迹,使被加工表面峰点电流密度更集中,磁场的搅拌作用,加快了电化学过程,使极间电流密度增大,蚀除速度加快,磁场电化学磁粒复合光整加工,与磁粒光整加工,电化学磁粒光整加工相比,提高了加工效率,改善了表面粗糙度。     

Prediction of cutting force, tool wear and surface roughness of Al6061/SiC composite for end milling operations using RSM

The results of mathematical modeling and the experimental investigation on the machinability of aluminium (Al6061) silicon carbide particulate (SiCp) metal matrix composite (MMC) during end milling process is analyzed. The machining was difficult to cut the material because of its hardness and wear resistance due to its abrasive nature of reinforcement element. The influence of machining parameters such as spindle speed, feed rate, depth of cut and nose radius on the cutting force has been investigated. The influence of the length of machining on the tool wear and the machining parameters on the surface finish criteria have been determined through the response surface methodology (RSM) prediction model. The prediction model is also used to determine the combined effect of machining parameters on the cutting force, tool wear and surface roughness. The results of the model were compared with the experimental results and found to be good agreement with them. The results of prediction model help in the selection of process parameters to reduce the cutting force, tool wear and surface roughness, which ensures quality of milling processes.     

Simulation and measurement of surface roughness via grey scale image of tool in finish turning

Study on the surface roughness of specimen is a significant field of research because this parameter affects the performance of the machined parts. Meanwhile, the evaluation of surface roughness of specimens using a vision system via the images captured from the specimen is an interesting method which is widely used. Although the effect of flank and crater wear has been investigated extensively in the past researches on surface profiles, some reports indicated that, in finish turning, the nose radius wear has a greater effect on the surface profile of specimen. Although, vibration can affect the surface profile of a specimen in rough turning, the final surface profile in the product used is usually shaped by finish turning that may not be affected by vibration using the robust machine tool. In this work, a machine vision was used to capture the images of the tool tip in-cycle. The 2-D images of the nose area of tool tips were used to simulate the surface profile of specimens in finish turning. The simulated images of specimens in a range of machining condition were detected using the algorithm of this work. The results showed that this method can be used successfully to simulate and evaluate the surface profile of a specimen in finish lathe machining as a fingerprint of the tool tip. This method can be used for forecasting the final surface profile in order to control the performance of products.     

用MasterCAM加工凸模零件的工艺分析

MasterCAM曲面加工一般分为粗加工和精加工,粗加工有七种路径,精加工有十种路径.粗加工是加工出大致形状,使用平刀,精加工是将工件加工成型,使用球头刀.在具体的加工时应选用适当的粗、精加工路径.从三角凸模的曲面特点及加工难点出发,分析了如何使用MasterCAM软件编制合理的刀具路径,使加工质量大为改善.     

数控立式磨床的开发设计

介绍一种新型磨削设备,着重介绍其设计思想、结构、附件应用范围.该机床研制可解决国内加工中大规格、扁平类、高精度淬火钢和特殊高硬度合金钢的表面加工,并使工件具有极高的加工精度.     

用金刚石端铣刀高速加工铝材

试验用设计的金刚石端铣刀进行了铝合金铣削试验,在常规的切削速度下用普通刀具加工零件,由于积屑瘤和毛刺的形成,往往引起刀具寿命短,加工表面质量差及切削刃质量差.在许多行业的铝合金加工技术中,较高的表面光洁度及切削刃质量很重要,也很需要.本试验的结果揭示出使用新设计的金刚石端铣刀高速切削铝合金,能加工出镜面表面,而不产生积屑瘤和毛刺.