箱体零件孔系加工工艺方案的探讨与实践

主要分析了箱体孔系的工艺性和难点,讨论了用车床改装成简易箱体镗床加工箱体孔系的可操作性和保证尺寸精度的可靠性问题。     

箱体孔系加工的座标尺寸精度和质量分析

本文介绍了箱体孔系座标尺寸的精度保证和孔系的加工质量分析。为了提高箱体孔系的加工质量，本文也介绍了工艺中应采取的措施。     

可调端面内孔组合镗刀

大批量生产的球墨铸铁或灰铸铁箱体类零件的同轴孔系,多数采用专用组合机床进行加工.在生产实践中,我们针对同轴孔系箱体零件端面与孔系轴线的垂直度、孔系的同轴度、孔系台阶面的平行度的形状位置精度、尺寸精度及表面粗糙度的技术要求,设计制造了可轴向、径向调整的端面内孔组合镗刀,如图所示.     

箱体类零件空间尺寸的测量方法

在生产加工中,许多零件的尺寸都是由空间尺寸构成,尤其是箱体类零件。箱体类零件通常涉及平行孔系、垂直孔系和相交孔系,这就使孔系与孔系、孔与孔之间构成了大量的空间尺寸。常规的测量工具无法实现空间尺寸的测量,需借助三坐标测量仪等精密测量仪器对工件空间尺寸进行检测。在未借助三坐标测量仪的情况下,通过自制专用检具,运用数学几何方法,将空间尺寸转换为平面尺寸,实现了对箱体类零件空间尺寸的测量。     

高精度中心架底座箱体孔系精度分析与控制

阐述了静压中心架箱体中各类孔系精度与控制,为了保证箱体内所安装零部件正确的相互位置,彼此能协调地工作,对各孔系的精度要求及加工工艺性作了深入的分析,同时对重要孔系的精度控制提出了合理的加工方案.     

坐标镗床调头镗孔的方法与精度分析

箱体加工中调头镗孔保证孔系同轴度公差是加工的难点。用坐标镗床加工单件、小批量箱体时,在孔系中各孔间跨距较大的情况下,多用调头镗孔的方法加工。用坐标镗床调头加工箱体孔系首先要选择与零件外形相适宜规格的机床和合理的定位基准(设计基准与定位基准重合),对孔系有高同轴变公差要求的箱体装夹应便于加工和测量。     

箱体平行孔系加工的坐标法原理及保证加工精度的方法

论述箱体平行孔系加工中坐标法的计算原理，阐明将孔系中心距平面尺寸链转化为线性尺寸链，并确定其坐标尺寸及公差的基本方法，为保证箱体孔系加工精度提供一种有效可靠的计算法。尤其适用于加工中心及数控镗、铣床等机床上孔系加工中的编程计算。     

箱体类零件孔系的检测

介绍了一种箱体类零件孔系检测的新方法。提出利用平板和高精度心轴及千分表来测量孔系同轴度和垂直度的方法,并在生产中取得了良好效果。     

主轴箱体孔系加工方法

箱体类零件是机械设备中最基础的组成部分,由它将机械部件中的的轴、轴承套、齿轮、轴承等有关零件按照一定的关系组装在一起而形成一个整体机床中的主轴箱体类零件是精度要求最高的一类箱体零件,数控卧式旋压机的主轴箱就属于这一类。本单位在数控卧式旋压机的主轴箱加工中使用捷克落地卧式镗铣床加工数控卧式旋压机的主轴箱体孔系,并以主孔系加工为例,介绍主轴箱孔系加工方法。通过边加工边测量的加工方法,调整支撑,测量镗床主轴挠度变化规律,确定主轴与支撑点之间的位置,对箱体孔系进行一次预加工。预加工后,测量其尺寸误差并分析原因,做调整后,最终加工出了满足图纸精度要求的主轴箱体孔系。通过分析该大型铸件箱体的加工难点及加工方法,并结合现有设备特点,对加工方法进行调整,实现了使用通用设备加工大型高精度零件的过程,解决了实际生产中遇到的问题,提高了生产效率,对此类零件的加工具有指导意义,具有实际工程意义。     

加工箱体端面及外止口的进给装置

减速箱是榨油机的关键零件，其箱体孔系的加工是箱体加工的关键工序。为此，设计制造了从箱体两面镗削的3轴专用组合机床（见图1）。箱体经专用双面组合专用铣床铣削两边平面后，在本专机上镜削箱体孔系。其中主轴孔端面有一外止口，因端面太大，固定刀排无法一次加工成（图1中     

Study of the Batch Production of Micro Parts Using the EDM Process

The micro machining of copper plates by the electrical discharge machining (EDM) process is described. Tungsten carbide was selected as the material for the electrode. Experiments were carried out on a conventional CNC-EDM machine to investigate machining of micro holes, and micro slots. The results show that micro holes, and micro slots can be successfully processed on a conventional CNC-EDM machine. To improve the productivity of micro parts using the EDM process, a batch production method of micro EDM using multi-electrodes has been studied. A new technique for preparing multi-electrodes has been developed. Results also show that the batch production of micro parts using EDM is feasible and that the batch production of micro parts using EDM process with multi-electrodes is very effective.     

A new tool wear estimation method based on shape mapping in the milling process

In the milling process, tool wear has a great influence on product machining quality, especially for a difficult-to-cut material. In this paper, a new approach based on shape mapping is proposed to acquire tool wear in order to establish an off-line tool wear predicting model for assessing the degree of wear and remaining useful life. The new approach maps tool wear shape into a metal material by milling holes mode after finishing each of the machining experiments. The metal material has low influence on tool wear compared to the experimental material. Thus, a series of mapped holes, which can represent the worn tool information, are formed on the metal material when finishing all milling experiments. These mapped holes on the metal material are analyzed according to all types of milling cutters in order to establish the relationship between the characteristic parameters of these mapped holes and tool wear. According to the established relationship, the characteristic parameters of these mapped holes are measured on the coordinate measure machine. The tool wear of each machining experiment can be obtained from the measured characteristic parameters of these mapped holes. The new tool wear estimation method does not require the stoppage of the machine tool and the removal of the cutter to measure tool wear in the process of conducting tool wear experiments. The new method can increase the machine tool efficiency of tool wear machining experiments and provide an efficient way to acquire tool wear in the process of establishing an off-line tool wear predicting model. In order to verify the new tool wear estimation method, a series of machining experiments were conducted on the five-axis machining center for cemented carbide cutting tool milling stainless steel. Experiments show that the shape mapping strategy of tool wear can allow for an effective assessment of tool wear and indicate good correlation with the expected wear characteristics and easily conduct tool wear experiments.     

万吨桨油孔和起吊孔的加工

在分析了万吨桨起吊孔和油孔的加工特点后,给出了使用小万向钻和特殊钻头以及间歇进给和退出的办法进行万吨桨油孔的深孔加工;使用小万向钻和专用工装采用先钻后镗,分层切削,逐渐去除余量,扩大孔径直到设计尺寸.经过实际生产的检验,所设计的方案取得良好的效果,可以满足万吨桨加工需要.     

用坐标法在数控机床上加工管板类工件的管孔位置度误差研究

以坐标法在立式加工中心加工大型管板类工件上的管孔为例,说明了工序尺寸链组成.对单个孔的位置度极限误差、任意两孔的中心距尺寸极限误差及其影响因素进行了分析,得出了单个孔的位置度极限误差、任意两孔的中心距尺寸极限误差与被加工孔在机床坐标系中的位置有关、与工件的移动路径和加工顺序无关的结论,对合理评价被加工件的质量具有普遍的指导意义.     

喷油嘴微孔电火花加工机床机电控制系统设计

喷油嘴喷孔加工质量直接影响发动机的燃料喷射和燃烧性能。喷油嘴喷孔机械钻削加工已难以适应高压力、微细喷孔喷油嘴发展的需要。微细电火花加工喷油嘴喷孔具有无宏观加工力、无毛刺、可加工微细喷孔以及可在热处理后加工等优点。文章结合自主设计研发的喷油嘴微细孔电火花加工机床,设计了机床的机电伺服控制系统,并进行了控制系统性能优化,进行了喷油嘴微细喷孔的电火花加工实验和工业应用,较好地满足了喷油嘴微细喷孔加工的工业需求。     

缸套孔系镗车复合数控机床的设计研究

根据柴油机机体缸套孔系结构及精度要求,提出了镗车复合加工新工艺,研究设计了双轴进给精镗止口、缸套孔、套筒偏心双层主轴单轴驱动精车止口端面立式数控机床,为稳定高效加工柴油机机体缸套孔系提供了新技术、新装备.     

高精度筒形超长孔加工方法

1提出问题小批量机械精加工中,一些零件中孔的长度超出了磨床的加工范围,传统工艺无法保证孔的精度,如图1中筒形零件,孔比较长,孔的公差小,切与外圆有同轴度要求,磨床无法一次加工成,此类零件一般精加工工艺为:(1)万能外圆磨床,夹φ60外圆磨φ50外圆,磨左端孔;(2)内孔磨床,自磨三爪,夹φ50外圆,磨右端孔。     

Design of ECM tool electrode with controlled conductive area ratio for holes with complex internal features

The design method of electrochemical machining (ECM) tool electrode with controlled conductive area for the machining of holes with given complex internal features was presented in this paper. Such holes were difficult to machine with traditional mechanical machining methods. In authors’ previous work, it has been proved that electrochemical machining (ECM) using tool electrode with controlled conductive area ratio was effective to machine many kinds of complex holes. However, it is considered that the inverse problem, i.e., designing of suitable tool electrode for given internal feature is of great importance for practical application. Therefore, in this work, the proposed ECM process was modeled to investigate the electric potential and current distribution in the electrolyte and on the electrodes’ surface, and the evolution of inner hole profile. Then, the relationship between conductive area ratio and the machining depth was investigated by a set of fundamental simulation experiments. Simulation result showed that suitable tool electrode with specific helical conductive area can be designed for the machining of hole with given internal feature. A prototype tool electrode with non-uniform conductive area ratio from its tip to the root was fabricated and used in the verification experiment. The machining result showed that a free-formed hole was successfully shaped and the inner hole profile is in well accordance with the given internal feature.     

改进精密镗床加工精度的方法应用

针对高精度孔在镗削加工中出现的孔表面质量不稳定和孔的圆柱度波动大的实际问题,通过对镗杆和机床丝杠的改进,使镗床的加工精度及其所加工内孔的重要指标精度均有了显著提高.     

大型箱体特大孔调头镗削工艺技术

采用普通铣镗床TPX6113-2加工大型箱体特大孔的调头镗削工艺综合了普通工艺装备与新技术,采用特殊装夹定位工艺方法,减少了反复装夹次数,保证了工件装夹定位的牢固性。设置辅助工艺基准点、线、面与数字的等量关系,控制等量误差精度,保证大孔调头后孔系加工中的同轴度。用平旋盘大孔镗刀架加工特大孔1 120+0.2+0.1和960+0.15+0.05mm的工艺与实践解决了中小型机床设备加工大型工件时,装夹定位难的问题和调头后定位难保证同轴度的问题。