發(fā)布時間：2018-03-03 12:18

  本文選題：幾何公差　切入點：公差規(guī)范　出處：《北京理工大學(xué)》2014年博士論文　論文類型：學(xué)位論文

【摘要】：幾何精度設(shè)計是保證機械產(chǎn)品質(zhì)量的重要環(huán)節(jié)，貫穿于結(jié)構(gòu)設(shè)計、裝配設(shè)計和工藝設(shè)計過程之中，對提高產(chǎn)品性能和制造效率具有重要的意義。隨著機械產(chǎn)品結(jié)構(gòu)日趨復(fù)雜、裝配精度要求不斷提高以及三維數(shù)字化設(shè)計與制造技術(shù)應(yīng)用的日益深入，三維偏差分析已成為產(chǎn)品研發(fā)中的熱點。為此，本文開展了機械產(chǎn)品幾何精度設(shè)計中的三維偏差分析技術(shù)研究，擬為幾何精度設(shè)計和提高產(chǎn)品裝配精度及一次裝配成功率提供了理論基礎(chǔ)和實現(xiàn)技術(shù)。 論文的主要研究內(nèi)容如下： （1）闡述了本課題的研究背景，詳細分析了公差建模、公差分析、公差綜合和計算機輔助公差設(shè)計技術(shù)的研究現(xiàn)狀，提出并總結(jié)了現(xiàn)有研究成果存在的問題與不足，給出了本課題的研究目標(biāo)和意義。 （2）針對幾何精度設(shè)計過程中幾何公差表達不規(guī)范的問題，提出了基于多色集合理論的幾何公差信息推理及其規(guī)范性驗證方法。通過構(gòu)建幾何公差信息本體模型，提煉并總結(jié)了幾何信息、方位信息、約束信息與公差信息之間的約束關(guān)系，提出了層次化的幾何公差信息推理結(jié)構(gòu)，并基于多色集合理論構(gòu)建了該層次結(jié)構(gòu)的多色集合模型，采用圍道矩陣對信息之間的約束關(guān)系加以描述，給出了公差類型和附加符號推理算法，在確�；鶞�(zhǔn)體系合理的基礎(chǔ)上實現(xiàn)了幾何公差信息的規(guī)范性驗證。 （3）針對零件之間裝配成功率計算精確性不高的問題，提出了基于配合接觸狀態(tài)的定位優(yōu)先級約束下零件裝配成功率計算模型。在裝配特征變動分析的過程中充分考慮了定位先后順序的影響，并分別針對平行平面配合、圓柱面配合、圓錐面配合和球面配合等間隙配合，分析了配合接觸狀態(tài)下裝配特征變動約束條件，構(gòu)建了零件裝配成功率計算模型，通過隨機模擬裝配特征的變動，實現(xiàn)了基于多對裝配特征定位的兩個零件之間裝配成功率的精確計算。 （4）針對面向幾何公差的裝配偏差傳遞路線難以搜索的問題，提出了基于變動向量空間的裝配偏差傳遞路線搜索方法。在全面地解析不同空間關(guān)系下特征之間理論約束方向的基礎(chǔ)上，根據(jù)線性相關(guān)理論歸納了特征之間實際約束方向的求解算法，提出了基于變動向量空間模型的約束方向范圍描述手段和偏差傳遞路線搜索算法，并給出了偏差傳遞路線的搜索流程，實現(xiàn)了三維偏差的裝配偏差傳遞路線搜索。 （5）針對面向幾何公差的裝配精度預(yù)測效率較低的問題，提出了基于多自由度偏差分布的裝配精度預(yù)測模型。通過構(gòu)建幾何誤差分布統(tǒng)一模型，并根據(jù)幾何誤差與自由度偏差之間的關(guān)系，全面解析了公差域和配合間隙約束下平面、直線和點在多個自由度方向上偏差的分布，再經(jīng)過對裝配偏差累積模型進行協(xié)方差處理，，構(gòu)建了基于自由度偏差分布的裝配精度解析模型，實現(xiàn)了面向幾何公差的裝配精度和裝配工藝能力指數(shù)的快速計算。 （6）針對工藝過程中定位基準(zhǔn)轉(zhuǎn)換引起的幾何公差轉(zhuǎn)換的問題，提出了基于公差變動矢量圖的幾何公差轉(zhuǎn)換方法。構(gòu)建了定位關(guān)系轉(zhuǎn)換有向圖及其數(shù)學(xué)模型，通過變動分析，建立了加工公差和基準(zhǔn)漂移約束下目標(biāo)特征的公差變動矢量圖，提出了基于橫截面的公差變動矢量圖包圍關(guān)系判定算法，推導(dǎo)了設(shè)計公差與加工公差的約束條件，實現(xiàn)了幾何公差的直接轉(zhuǎn)換。 （7）結(jié)合論文的研究成果以及相關(guān)科研課題，介紹了自主開發(fā)的公差信息管理與分析軟件系統(tǒng)的總體架構(gòu)、功能模塊和軟件界面，并以航天器艙段與設(shè)備裝配為實例驗證了系統(tǒng)的可行性和有效性。
[Abstract]:Geometric precision design is an important link to ensure the quality of mechanical products, through structural design, assembly design and process design, has an important significance to improve product performance and manufacturing efficiency. With the mechanical product structure is becoming increasingly complex, and continuously improve the assembly precision and the three-dimensional digital design and manufacturing technology is used widely, 3D deviation the analysis has become a hot topic in product research and development. Therefore, this paper carried out the 3D deviation of mechanical products in geometric precision design analysis technology research and implementation technology, to provide theoretical basis for the design of geometric precision and improve the precision of assembly and an assembly success rate.
The main contents of this paper are as follows:
(1) elaborated the research background of the subject, analyzed the research status of tolerance modeling, tolerance analysis, tolerance synthesis and computer aided tolerance design in detail, and put forward and summarized the existing problems and shortcomings of the existing research results, and gave the research objectives and significance of this topic.
(2) according to the geometric precision design of process tolerance expression is not regulated, presents the geometric tolerance information reasoning and normative verification method based on polychromatic sets theory. By constructing geometric tolerance information ontology model, refining and summarized the geometric information, position information, constraint relation between constraint information and tolerance information, put forward the hierarchical structure and geometric tolerance information reasoning, based on polychromatic sets theory to construct the hierarchical structure of the polychromatic set model, using contour matrix of constraint relations between information to describe the given tolerance types and additional symbolic reasoning algorithm, ensure reasonable benchmark system realizes geometric tolerance information standardization verify.
(3) the parts assembly success rate calculation accuracy is not high, the positioning of the contact state under precedence constraints with assembly success rate based on the calculation model. In the process of assembly feature change analysis considering influence of positioning sequence, and were aimed at the plane parallel with the cylinder with cone with the surface and spherical with clearance fit, analyzed with contact state changes of assembly feature constraints, construction assembly success rate calculation model, the stochastic simulation of assembly feature changes, realize the accurate calculation between the two parts of the assembly feature location based on assembly success rate.
(4) for assembly oriented deviation geometric tolerances route difficult to search problems, put forward the change of assembly deviation vector space search method based on the transmission line. Based on the comprehensive analysis of different spatial relations characteristic under the direction of the theory of constraints, algorithm according to the linear correlation theory summed up the direction of actual constraints among the features. The proposed constraint direction vector space model to describe the change means and deviation transfer route search algorithm based on the error and gives the route search process, realize 3D assembly deviation deviation route search.
(5) according to the assembly precision prediction efficiency oriented geometric tolerances with the problem of low prediction model is proposed based on multi degrees of freedom distribution assembly accuracy. By constructing geometric error distribution model, and according to the relationship between the geometric error and deviation of degree of freedom, a comprehensive analysis of the tolerance domain and the gap with the constraint plane. The distribution of the lines and points in multiple degrees of freedom direction deviation, and then after the assembly deviation cumulative model covariance processing, constructs the degrees of freedom distribution assembly accuracy based on the analytical model, the fast calculation for assembly precision and assembly process capability index of the geometric tolerances.
(6) the conversion conversion problem caused by geometric tolerances for positioning in the process of reference, put forward the conversion method of geometric tolerance changes based on the vector graph. Construct a directed graph based model transformation between positioning and mathematics, through change analysis, established the process tolerances and base drift under the constraint of target feature vector change tolerance the cross section of the tolerance, change vector relation decision algorithm based on the derived constraints on design tolerances and machining tolerances, realizes the direct conversion of geometrical tolerances.
(7) according to the research results and related research, introduces the overall architecture of independent development of tolerance information management and analysis software system, function module and software interface, and the assembly of spacecraft cabin and equipment as an example to validate the feasibility and validity of the system.

【學(xué)位授予單位】：北京理工大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：TH122


本文編號：1561003