油泵壳体的模具设计
油泵壳体的模具设计,油泵,壳体,模具设计
The fast mould integrates the systematic precision and guarantees that the system is studied
Summary : Recommend with RP fast of technology and cast maturity manufacture functional CAE system of products of craft, have analysed the factor influencing precision of the products, has proposed analysing the precision at stage of three main shaping with the non-linear finite element, adopt pattern-recognition theory, error theory, neural network method to deal with the error and feedback the problem, carry on error compensate revise and prediction of machining accuracy , improve final method of product quality.
Keyword: CAE; RT; Feedback
1 preface
Fast prototype technology (& of Rapid Prototyping Manufacturing, abbreviate RP or RPM as, urged directly by the part CAD model, adopt the material accurate prototype or part manufacturing technology which piles up the complicated three-dimensional entity, it is each on the basis of being dispersed /pile up by shaping manufacturing approach not new-type of the principles.
Rapid shaping technique already can make and include resin, plastics, paper, paraffin wax, pottery prototype of material successfully very much, but can only do the function experiment in the limited metal used for substituting really of occasion and other type function parts as the functional part. With increase and constant development of technology of demand, fast prototype technology to fast prototype / direction in which the part is being made develop.
Utilize RP technological shaping function part, especially metal a kind of main method of part a switch technology, called the fast technology of mould(RT, Rapid tooling). Because traditional mould complicated consuming time and long costly to make course, become design and bottleneck that make often, use RP technology make fast economic mould become RP main motive force of technical development one of. Paul think from PR to RT shaping the second leap of technical development fast.
The final purpose of making and shaping is products and service offered and meet the demands. RP technology become front technology of manufacturing industry with a great deal of superiority their, but because limitation restriction extensive application their of material; Traditional technology such as cast, forge and press and develop for a long time, relatively ripe already, but can't meet the needs of fast flexibility of information age , within future one period, must conbine rapid shaping technique and traditional shaping technology together , realize melting quickly and make.
2 RP and RT system integration
New product development most high cost have, man-hour longest stage to make the physical model involved, namely prototype manufacture process. RP technology use fast inspection and fast manufactures of different model that part design for mainly. Its basic principle and forming process are: Designed the computer three-dimensional curved surface entity's model of the necessary part by CAD software first , namely electronic model; According to technological requirement, go on the strata it according to certain thickness , turn the original three-dimension electronic model into two-dimentional level information (sectional information); And then carry on certain treatment of the data after the strata, put into and process parameters, produce the numerical control code; Until computer control, numerical control system process by level way process each thin layer and make they automatic sticking and shaping in succession in an orderly manner.
RT changes RP prototype into the technology of the tool and mould with various kinds of methods . A method among them is to change the prototype into a pottery type, utilize the method to cast to change into a metal type . And RT manufacture of technology intergration accurate to cast mould method meet modern industry towards many variety, turn batch request of development into with RP prototype, it known as" it is flexible tool " method 5 ,its craft of routes.
3 integrated system make functional precision of product analyse
Can find out from CAD final precision of product decide by manufacture error at each stage from model to fast prototype course in products.
(1)CAD modeling among the course, because of modeling limitation of software, can describe accurate often as to complicated curved surface;
(2)STL division of file among the course, because STL file layout mistake that modelling appear in the course sensitive to geometry, mistake these bring through STL file into and get RP modelling among the craft, some influence RP modelling course 3 these of craft seriously, 4 these . And STL file one approach the wanton surface of the room the triangle with level, therefore can only it is at CAD geometrical property among system therefore 3 on part since express approximate therefore.
(3)RP craft through to pile up and succeed the object prototype next life material, a lot of craft course is also following the changing of the material , such as FDM and SLA craft. So, the forming process of RP is not only that the machinery of a material piles up course, a height coupling, non-linear thermodynamics course. There are thes influence factor of the precision of this course: Thickness of material parameter, power of laser, strata, scanning route,etc..
(4)Change precision loss of craft depend on and change craft material, conversion method used,etc..
(5)It is the stage that the precision loses the most in the whole craft course that the metal pours the course. Usually, the first several in 10*10 error of stage - 2 mm order of magnitude, and metal solidify size change of course in several even a dozen mm.s of order of magnitude, so, the improvement of the precision of the final products depends on this stage to a great extent. There are thes factor influencing its precision: Material nature, for instance material density, elastic mould amount, heat conduction rate, specific heat, line coefficient of expansion,etc., especially the high temperature hot thing parameter of the metal, the heat transfer characteristic between the metal and type, position of watering, rising head ,etc..
4 integrate the precision of the systematic products and guarantee the system
In the actual production, adopt and try on law come and guarantee final precision of product by mistake often. With the development of technology of the computer and to lowering costs, realizing the requests of digitization, course controllability, necessary to adopt computer integrated manufacturing approach, go on computer simulation emulation study to whole course. CAE (Computer Aided Engineering, project computer auxiliary ) including fairy victory make, flexible manufacturing, at the same time project, make etc. fictitiously. Introduce CAE technology, can draw the craft route again. If regard the middle course as " the black box ", from the craft route to the products of CAD model; This fast, many return circuit error with corresponding course controls and the reponse system.
5 errors feedback system research
In this CAE system, the error exists at every stages.
In CAD modelling , divide in the course of STL file , it is because of the limitation of the modelling software that precision is lost, improve the quality of the software, can reduce the error .
At RP prototype fabrication stage , change craft stage and metal to pour stage, involve the hot, strength coupling question, quote the non-linear finite element method , under the three-dimensional flute Karl's coordinate, according to the conservation principle of energy, can draw :
(1)
Exert hot stress and external force(such as border terms) that temperature cause as the strength load the object and then, try to get total deformation amount. After drawing the errors of every stages, can set up error reponse system . The error reponse system belongs to and closes the control system of the ring . A main content of it is the research that transmits function out of shape. Under it is at flute not three-dimensional Karl coordinate, whether calculate and error after being the out of shape can express for deformation that get for:
e(x,y,z) =P ideal (x, y, z)- p reality (x, y,z) (2)
If use Δ d (x, y, z) to show the change matrix of the real whole form , g (x, y, z) shows the matrix of controlling, the feedback control of the whole course can be described as:
Δ d (x, y, z) =g(x,y,z) e (x, y,z) (3)
E (x, y, z) is the algebraical sum of each course, namely, if does not consider the error of CAD modelling course , and e 1 (x, y,z),e 2 (x, y,z),e 3 (x, y,z) show respectively there aren't RP the error, the conversion craft error and the metal of course where the prototypes makes,
e(x,y,z) =(x, y,z)+e 3 (x,y, z) (4)
The present question is, set up proper g (x, y, z),make Δ d (x, y, z) can disappear to and smaller than range that a certain error allows δ quickly , namely satisfied:
<δ of Δ d (x, y, z) (5)
G (x, y, z) embodies us to the whole understanding of deforming the course, it must real-time reflection products out of shape with CAD model out of shape coupling relation. And will change with the changes of the border condition out of shape and material parameter .
Because the whole course is that more than one variable, complicated three-dimension input more close the control system of the ring non-linearly, perhaps there is a coupling relation between each variable, so, influence g (x, y,z) factor the a lot of,very it it is difficult to be describe with unified mathematics formula, so, the author puts forward the method to use neural network, train g (x, y,z),make Δ d (x, y,z) reach require.
Utilize the neural network to have advantage taught oneself to practise, can reduce the error and feedback the demand for the craft data of the question greatly , and benefit systematic expansion. And because close correcting function to the error of system of ring , may cause systematic unstability . Adopt neural self-adaptation of network, learning method, can raise system stupid and getting wonderful.
6 conclusions
RP technology is a fast-developing new developing manufacturing technology, RP, and RT integrated system that technology combine together to make functional main method of part with RP technology nowadays, the precision of raising this fast flexible system is nowadays urgent problem that is solved . This text has analysed that influences the factor of the precision of the products in this flexible manufacturing system, have proposed analysing the precision at stage of three main shaping with the non-linear finite element, adopt pattern-recognition theory, error theory, neural network method to deal with the error and feedback the problem, carry on error compensate revise and prediction of machining accuracy , improve final method of product quality.
Selected from " the electromechanical project "
快速模具集成系统精度保证体系研究
摘要: 介绍了利用RP技术的快速性和铸造工艺的成熟性制造功能性产品的CAE系统，分析了影响产品精度的因素，提出了用非线性有限元分析三个主要成型阶段的精度，采用模式识别理论、误差理论、神经网络方法处理误差反馈问题，进行误差补偿修正和加工精度的预报，提高最终产品质量的方法。
关键词：CAE；RT;反馈
1 前 言
快速原型技术（Rapid Prototyping & Manufacturing,简称RP或RPM）是指在计算机控制与管理下，由零件CAD模型直接驱动，采用材料精确堆积复杂三维实体的原型或零件制造技术，是一种基于离散/堆积成型原理的新型制造方法。
快速成型技术已经能非常成功地制作包括树脂、塑料、纸类、石蜡、陶瓷等材料的原型，但往往不能作为功能性零件，只能在有限的场合用来替代真正的金属和其它类型功能零件做功能实验。随着需求的增加和技术的不断发展，快速原型技术正向快速原型/零件制造的方向发展。
利用RP技术成型功能零件尤其是金属零件的一种主要方法是转换技术，称为快速模具（RT，Rapid tooling）技术。由于传统模具制作过程复杂、耗时长、费用高，往往成为设计和制造的瓶颈，因此应用RP技术制造快速经济模具成为RP技术发展的主要推动力之一。Paul[1]认为从RP到RT是快速成型技术发展的第二次飞跃。
制造和成型的最终目的是要提供满足要求的产品和服务。RP技术以其诸多优越性而成为制造业的前沿技术，但因为材料的局限性制约了其更广泛的应用；传统技术如铸造、锻压等经过长期发展，已相对成熟，但不能适应信息时代的快速柔性要求，在未来一段时期内，必须将快速成型技术与传统成型技术结合起来，实现敏捷化制造。
2 RP与RT系统集成
新产品开发中成本最高、工时最长的阶段就是制造所涉及的物理模型，即原型制造过程。RP技术主要用于零件设计的快速检验以及各种模型的快速制造。其基本原理和成型过程是：先由CAD软件设计出所需零件的计算机三维曲面实体模型，即电子模型；然后根据工艺要求，将其按一定厚度进行分层，把原来的三维电子模型变成二维平面信息（截面信息）；再将分层后的数据进行一定的处理，加入加工参数，生成数控代码；在计算机控制下，数控系统以平面加工方式有序地连续加工出每个薄层并使它们自动粘接而成型。
RT就是用各种方法把RP原型转换成工模具的技术。其中一个方法是将原型转换成陶瓷型，再利用铸造的方法转换成金属型。利用RP原型与RT技术集成的制造精密铸造模具方法适应了现代工业向着多品种、变批量发展的要求，被称为“柔性工具”方法[5],其工艺路线.
3 集成系统制造功能性产品的精度分析
从CAD模型到快速原型到产品的过程可以看出，最终产品的精度是由每个阶段的制造误差决定的。
(1)CAD建模过程中，由于建模软件的局限性，对于复杂的曲面常常不能精确地加以描述；
(2)STL文件的划分过程中，由于STL文件格式对几何造型过程中出现的错误不敏感，这些错误通过STL文件带入到RP造型工艺中，有的将严重影响RP工艺的造型过程[3，4]。而且，STL文件用平面三角形面片来逼近空间的任意表面，因而只能近似地表示零件在CAD系统中的几何特征[3]。
(3)RP工艺是通过材料的堆积来生成物体原型，许多工艺过程还伴随着材料的相变，如FDM和SLA工艺。所以，RP成型过程不只是一个材料的机械堆积过程，还是一个高度耦合、非线性的热力学过程。这一过程的精度影响因素有：材料参数、激光功率、分层厚度、扫描路径等。
(4)转换工艺中的精度损失取决于转换工艺所使用的材料、转换方法等。
(5)金属浇注过程是整个工艺过程中精度损失最大的阶段。通常，前几个阶段的误差在10×10-2mm数量级，而金属凝固过程的尺寸变化在几个甚至十几个毫米数量级，因此，最终产品精度的提高很大程度上取决于这个阶段。影响其精度的因素有：材料性质，如材料密度、弹性模量、导热率、比热、线膨胀系数等，尤其是金属的高温热物性参数，金属与型腔之间的传热特征，浇、冒口的位置等。
4 集成系统产品精度保证体系
实际生产中，常常采用试错法来保证最终产品的精度。随着计算机技术的发展以及对降低成本、实现数字化、过程可控性的要求，有必要采用计算机集成制造方法，对整个过程进行计算机模拟仿真研究。CAE（Computer Aided Engineering,计算机辅助工程）包括灵捷制造、柔性制造、同时工程，虚拟制造等。引进CAE技术，可以把工艺路线重新绘制。如果把中间过程看作“黑匣子”，则由CAD模型到产品的工艺路线；此过程相应的快速、多回路误差控制与反馈系统。
5 误差反馈系统研究
在此CAE系统中，误差存在于每一阶段。
在CAD造型、划分STL文件的过程中，精度的丢失是由于造型软件的局限性，提高软件的质量，可以降低误差。
在RP原型制造阶段、转换工艺阶段和金属浇注阶段，涉及热、力耦合问题，引用非线性有限元方法，在三维笛卡尔坐标下，根据能量守恒原理，可以得出：
(1)
再将温度引起的热应力和外力（如边界条件）之和作为力载荷施加到物体，求得总变形量。得出每一阶段的误差之后，可以建立误差反馈系统。误差反馈系统属闭环控制系统。它的一个主要内容是变形传递函数的研究。在三维笛卡尔坐标下，由计算得到的变形前和变形后的误差可以表示为：
e(x,y,z)=p理想(x,y,z)-p实际(x,y,z) (2)
如果用Δd（x,y,z）表示实际整体形状的变化矩阵，g(x,y,z)表示控制矩阵，则整个过程的反馈控制可以描述为：
Δd（x,y,z）=g(x,y,z) e (x,y,z) (3)
e(x,y,z)是每个过程的代数和，即，如果不考虑CAD造型过程的误差，且e1(x,y,z)，e2(x,y,z)，e3(x,y,z)分别表示RP原型制造的误差、转换工艺过程的误差和金属浇注过程的变形量，则
e(x,y,z)=e1(x,y,z)+e2(x,y,z)+e3(x,y,z) (4)
现在的问题就是，设置适当的g(x,y,z)，使Δd（x,y,z）能够很快地收敛到小于某个误差允许的范围δ，即满足：
Δd（x,y,z）＜δ (5)
g(x,y,z)体现出我们对整个变形过程的理解，它必须实时的反映产品变形和CAD模型变形的耦合关系。而且还要随变形边界条件和材料参数的变化而变化。
由于整个过程是一个多变量、多输入的复杂三维非线性闭环控制系统，各个变量之间可能存在耦合关系，因此，影响g(x,y,z)的因素很多，很难用统一的数学公式描述，因此，作者提出应用神经网络的方法，训练g(x,y,z)，使Δd（x,y,z）达到要求。
利用神经网络具有自学习的优点，可以大大减少误差反馈问题对工艺数据的需求，并且便于系统的扩展。而且由于闭环系统对误差的校正作用，可能会导致系统的不稳定。采用神经网络的自适应、自学习方法，可以提高系统的鲁棒性。
6 结论
RP技术是一个正在快速发展的新兴制造技术，RP和RT技术相结合的集成系统是当今利用RP技术制造功能性零件的主要方法，提高此快速柔性系统的精度是当今急迫解决的问题。本文分析了影响此柔性制造系统中产品精度的因素，提出了用非线性有限元分析三个主要成型阶段的精度，采用模式识别理论、误差理论、神经网络方法处理误差反馈问题，进行误差补偿修正和加工精度的预报，提高最终产品质量的方法。
选自《机电工程》
9
摘 要
本次设计的题目是油泵壳体的模具设计。通过对制件的工艺分析，确定了模具的工艺方案。共分为两次拉深和一次冲孔翻边。本说明书主要阐述了油泵壳体的第一次拉深和冲孔翻边模具设计的基本过程及主要计算数据。
全篇共分为三章。第一章是设计油泵壳体模具的工艺方案的确定，主要根据所给制件特点加以分析，设计出合理的模具，这里共设计出两套模具。第二章是落料拉深复合模的设计，其中包括一些典型结构的选择和一些非标准零件的设计。第三章是冲孔翻边复合模的设计，包括各种模具零件的选择和一些零件尺寸的计算。第一套模具是典型的结构，第二套模具则根据制件工艺要求进行了部分创新。
鉴于本人的水平所限，在设计中肯定有不足之处存在，也会有很多错误出现，恳请评阅老师和各位读者包涵并且批评指正。
关键词：拉深 冲孔 翻边
Summary
The topic designed this time is the mold design of the shell of an oil pump. Through analysing to the craft which makes one , have confirmed the craft scheme of the mould. Divide it in order to draw and wash hole turn-ups with once deeply twice altogether. Manual this explain oil pump shell draw dark washing hole basic course , turn-ups of mold design and mainly calculating the datum for the first time mainly.
The whole one is divided into three chapters altogether. Chapter one the sureness of craft scheme of designing shell mould of the oil pump, the main foundation gives and makes a characteristic to analyse , design the rational mould, design two sets of moulds altogether here. Chapter two the blanking draws the design of the deep complex mould , including some choices of typical structure and the designs of some non-standard parts. Wash hole turn-ups complex design of mould , include various kinds of mould choice and some part calculation of size of part. The first set of moulds is the typical structure, the second set of moulds has innovated partly according to making a technological requirement.
Seeing that my level restricts, must there are weak points to exist in the design, a lot of mistakes will appear too , will earnestly ask to read and appraise the teacher and every reader and forgive and make a comment.
Keywords: Draw deeply Wash holes Turn-ups
目 录
第一章 工艺方案的确定 ……………………………………………………… 1
第二章 落料拉深复合模的计 ……………………………………………… 3
第三章 冲孔翻边复合模的设计 ……………………………………………… 15
毕业设计总结 ………………………………………………………………… 24
参考文献 ………………………………………………………………………… 25
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