缸体凸轮轴孔机床托刀架的改进

DU4900缸体双面卧式粗镗、扩、钻孔组合机床是大连机床集团为山东潍坊柴油机股份有限公司设计生产的,用于加工缸体的主轴孔与凸轮轴孔.该机床加工时,刀具采用滚动导向,滚动导套设置在夹具上.由于主轴与刀杆浮动联接,所以设计了一个托刀架,将悬伸的刀杆托起,以便于更换刀具和调刀时重新引导刀杆进入滚动导套.     

齿轮泵壳体孔的加工方法及夹具设计

齿轮泵壳体上有两个孔要求的加工精度高。在中、小批量生产时,一般都使用通用机床和专用工装来加工,这种加工方法很难达到精度要求。我校实习工厂生产这一零件时,从加工方法、刀具、夹具方面进行不断改进,较好地解决了这一问题,使加工质量稳定可靠。1　泵体孔的精度要求和加工方法图1为齿轮泵体加工两孔的工序简图。从图1可知:小孔125为7级,且两孔极限尺寸不同;大孔Ｒ1841接近8级;有同轴度、垂直度、位置度公差要求,特别是位置度公差很小。因此,孔的加工难度大。经过反复试验、改进,现采用如下加工方法:将两孔加工放在两端面、4-9孔加工工序…     

深孔钻床加工偏心细长孔的方法

介绍了深孔钻加工偏心细长孔的方法。与用镗床加工相比,用深孔钻床可以提高加工效率,降低成本。     

内孔反向组合刀具的设计及应用

采用内孔反向组合刀具,一次装夹就可以加工同轴度要求很高的两侧台阶内孔套类零件,特别是内孔孔径较小的套类零件,大大提高了此类零件的位置精度,加工效率高、操作方便。     

一对有孔距要求的异型孔加工

介绍了加工有孔距的两异型孔的工艺,通过冲压加工,圆满地解决了加工、装配过程中出现的种种问题,达到了使用要求。     

基于Cimatron软件的模具定位孔加工

在分析Cimatron常用的几种定位孔加工方法的基础上,探索出了用Cimatron软件的POCKET加工方法生成全螺旋加工刀路,实现定位孔加工的新方法,结果表明该方法既可以保证加工精度,又可以提高加工效率,而且具有配备刀具少、加工质量稳定等优点,值得推广使用。     

前桥锁销孔加工机床

文章介绍了一种新型的前桥锁销孔加工的工艺方法.通过对前桥锁销孔加工工艺方法的分析、调查研究,以及大量的生产实践的验证,提供了一种新型的铣削交叉孔的加工工艺方法.该方法具体应用为:一工位用钻头加工实体部分;二工位用铣刀加工两孔相交部分;三工位用钻头钻通孔余下部分;四工位用铰刀通铰全孔.经过一系列的改进,成功地加工出合格的产品,为高精度交叉孔的加工提供了一种新工艺.     

工件定位销孔的刚性加工

在内燃机机体、缸盖、齿轮室等工件的加工生产中 ,定位销孔是其他工序的基础 ,也是保证装配后整机性能的关键。所以其位置精度要求很高 ,一般都要求在 0 .0 3mm以内。因此定位销孔的精度成为影响内燃机质量的一个重要因素。以我公司为例 ,以前的定位销孔加工为导套式加工 ,定位销孔的精度受夹具孔座标的误差 ,刀具、导套、衬套、夹具立臂间的配合误差 ,刀具本身的跳动误差 ,夹具的夹紧变形 ,滑台的运动刚度等因素的影响 ,很难保证加工精度 ,机体、缸盖的定位销孔位置精度在 0 .0 8mm左右 ,齿轮室的定位销孔位置精度在 0 .10mm左右。为解决…     

一种新型的加工锥孔的装置

１　前言锥孔通常可在普通车床、仿形车床、数控车床上加工。如果在一个零部件上有不同锥度的孔，用上述万能设备加工，则生产率低，质量不稳定。我厂新研制的镗锥孔工艺装置安装在组合机床上，加工不同锥度的孔，取得了很好的效果。２　结构与原理该结构（图１）是由大镗杆２、推杆３、导向定位键４、销轴５、导向套６和小镗杆７等主要零部件组成，安装在相应规格的镗削头或专用多轴镗削头的主轴１上。镗削头按表１中的型号配置。小镗杆７装配在按技术要求加工成斜度的大镗杆２内，由导向套６保证小镗杆７的轴向运动精度和润滑，导向定位键…     

深孔精密液压元件内孔加工工艺的研究

深孔精密液压元件加工的关键在于深孔的精密加工。目前国内深孔加工技术尚未成熟,此类产品绝大部分只能依靠进口。结合某公司伺服油缸、高压油缸、摆动缸深孔元件的加工,通过对密封机制与密封失效的分析,阐述深孔精密液压元件深孔精密加工的重要性,提出深孔精密元件加工的工艺路线。     

重型油缸侧缸BTA深孔套料加工刀具过度磨损崩刃的研究

深孔加工的BTA套料工艺方式,工艺系统是处于内、外切削液和切屑包容的环境中,系统的任何微小外扰,都会造成系统的失稳,引起钻杆振动和刀具非正常磨损与崩刃。通过分析高精度、重型油缸侧缸的BTA深孔套料工艺,提出工艺系统失稳的解决措施,通过实际生产验证了措施的有效性。通过工艺优选试切试验,找出适合重型油缸深孔套料的一些加工参数,对生产中类似工件深孔工艺参数的选取具有参考价值。     

GFRP低频轴向振动制孔的钻削力特性和套料钻磨损分析

GFRP的套孔钻削过程中极易产生分层、撕裂等加工损伤,其与轴向钻削力直接相关。为提高GFRP的制孔质量,采用新型金刚石薄壁套料钻,结合低频轴向振动加工技术,建立单颗磨粒的运动学模型和动力学模型,试验研究GFRP制孔中的轴向力变化规律,并对套料钻的烧焦概率、自动落料率进行分析。结果表明：对比常规钻削,低频振动钻削时的瞬时进给量和轴向力比常规钻削时的大,且随着振幅的增加,轴向力也随之增大;低频振动钻削和常规钻削时的轴向力皆随进给速度的增加而增大,随主轴转速的升高而降低。同时,低频振动钻削时磨粒间断性地参与钻削,大大降低了套料钻的烧焦概率,提高了其自动落料率,自动落料率高达88.24%,可实现GFRP的连续批量制孔。     

Trepanning of Al2O3 by electro-chemical discharge machining (ECDM) process using abrasive electrode with pulsed DC supply

Electro-chemical discharge machining (ECDM) of electrically non-conductive high-strength–high-temperature-resistant ceramics such as aluminium oxide (Al₂O₃) by trepanning method (i.e. orbital motion of tool) has shown the possibility of drilling large size holes by comparatively smaller electrodes efficiently and economically. However, at greater machined depth, the conventional electrode configurations and machining parameters show that machining performance gradually deteriorates with increase in tool depth and finally cause micro cracks on the machined surface due to thermal shocks at high voltage. To reduce this problem and to enhance the machining performance during trepanning operation of Al₂O₃, a spring fed cylindrical abrasive electrode of 1.5 mm diameter has been used under the effect of the three most influential parameters, namely, pulsed DC supply voltage, duty factor and electrolyte conductivity, each at five different levels to assess the volume of material removed, machined depth and diameteral overcut. The results obtained from this study revealed that pulsed DC has reduced the tendency of cracking at high supply voltage compared to smooth DC and the machining ability of the abrasive electrode was better than copper electrode as it would enhance the cutting ability due to the presence of abrasive grains during machining. In addition to this, trepanning provides the scope for drilling bigger holes.     

钛合金叶栅套料电解加工表面质量研究

针对TC4钛合金叶栅套料电解加工易点蚀、表面质量差的问题,开展了直流和脉冲电解加工对比研究,设计了脉冲电解加工正交试验,优化了脉冲电压、频率、占空比和加工速度等参数。试验结果表明:脉冲电解加工能减少钛合金点蚀凹坑,提高表面质量,在22 V电压、80%占空比和1000 Hz频率时,加工叶型表面完整无点蚀,加工效率高。     

Investigation of underwater laser drilling for brittle substrates

The aim of this paper is to present and discuss data on underwater laser drilling techniques for brittle substrates. Drilling under water reduced substrate defects that typically result from conventional laser drilling in air. In this study, the substrates were submerged 1 mm beneath the water surface. A CO₂ laser was used to drill holes into LCD glass and alumina substrates. It was found that the underwater laser drilling quality for these materials is much better than that from laser drilling in air. Underwater laser drilling reduced the phenomena of micro-cracking and minimized the size of the area affected by heat from the laser. Also in this study, single-hole drilling and array-holes drilling by percussion and trepanning were conducted and analyzed both in air and underwater. The minimum distance between the two neighbour holes that can be obtained was much shorter in water than in air. The SEM photographs of the holes illustrate the contrast in drilling quality. The relationship between laser power, pulse repetition rate, and the hole quality was also evaluated.     

Optimization of guide pads for the BTA deep hole drilling of high alloyed steels by microfinishing

The boring and trepanning association deep hole drilling of materials with a high tendency to adhesion, such as high alloyed-steels, is characterized by a poor surface quality of the bore hole. Material particles adhere to the guide pads that are positioned on the circumference of the drill head and that are normally responsible for the outstanding workpiece quality. In order to prevent this mechanism the guide pads were coated with an innovative amorphous and tetrahedral bonded (ta-C)-coating. This coating has a reduced friction coefficient of 0.1 against steel and a hardness coefficient of about 7,000 HV. To use the benefits of this ta-C-coating the pre- and the after-treatment of the uncoated carbide substrate and ta-C-coated guide pads are essential. For these process steps a microfinishing process was carried out as an alternative to the conventional treatment by polishing and brushing. The microfinishing of the uncoated guide pads effects a smooth surface that is necessary for an optimum bonding strength of the ta-C-coating at the carbide substrate. Furthermore the chamfer edge in the lead-in-area is rounded which reduces the mechanical load at this specific area during the process. The finishing process of the coated guide pads reduces the coating defects and improves the friction coefficient. Thus, the wear behavior of the guide pads is improved because of the better friction conditions during the drilling process of high alloyed steels.     

浅析模具高速加工技术

介绍了高速加工的定义及其与传统加工方式相比的技术优势,详细阐明了由于模具加工的特殊性以及高速加工技术的自身特点,对模具高速加工系统（加工机床系统、刀具系统、CAD/CAM技术等）及加工工艺策略提出的更高要求.     

半固态材料成形评述

半固态加工与固态加工、液态加工同属金属加工领域,是金属材料热加工的新兴技术。主要介绍了半固态加工 的应用及未来发展趋势,以期推动其理论研究和工业发展。     

基于MasterCAM的T形楔块数控加工工艺分析

对T形楔块加工零件进行了结构分析和加工技术要求分析,详细地分析了常规加工工艺存在的问题,并对常规加工工艺提出了新的加工工艺.实践证明,经改进后的加工工艺,从加工时长、NC文件大小、刀具成本等方面都有了质的飞跃.     

半固态材料成形应用

半固态加工是金属材料热加工的新兴技术，它与固态加工、液态加工同属金属加工领域：主要介绍了半固态金属浆料的制备、半固态加工的工艺方法、半固态加工的应用及未来发展趋势，以期推动其理论研究和工业发展。